DH Instruments PG7000 - V2.03, PG7202 - V2.03, PG7102 - V2.03, PG7302 - V2.03, PG7601 - V2.03 Operation And Maintenance Manual

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PG7000™ PISTON GAUGES
PG7102™, PG7202™,
PG7302™, PG7601™
(Ver. 2.03 and Higher)
Operation and Maintenance Manual
©1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
High pressure liquids and gases are potentially hazardous. Energy stored in these liquids and gases
can be released unexpectedly and with extreme force. High pressure systems should be assembled and operated only by personnel who have been instructed in proper safety practices.
© 1998 - 2002 DH Instruments, Inc. All rights reserved.
Information in this document is subject to change without notice. No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without the express written permission of DH Instruments, Inc. 4765 East Beautiful Lane Phoenix Arizona 85044-5318 USA.
DH Instruments makes sincere efforts to ensure the accuracy and quality of its published materials; however, no warranty, expressed or implied, is provided. DH Instruments disclaims any responsibility or liability for any direct or indirect damages resulting from the use of the information in this manual or products described in it. Mention of any product or brand does not constitute an endorsement by DH Instruments of that product or brand. This manual was originally composed in English and was subsequently translated into other languages. The fidelity of the translation cannot be guaranteed. In case of conflict between the English version and other language versions, the English version predominates.
DH Instruments, DH, DHI, PG7000, PG7102, PG7202, PG7302, PG7601, CalTool and COMPASS are trademarks, registered and otherwise, of DH Instruments, Inc.
Swagelok is a registered trademark of the Swagelok Company. Krytox is a registered trademark of the Dupont de Nemours Company.
Products described in this manual are manufactured under international patents and one or more of the following U.S. patents: 5,142,483, 5,257,640, 5,331,838, 5,445,035. Other U.S. and international patents pending.
Document No. 550099k 020612 Printed in the USA
© 1998-2002 DH Instruments, Inc
TABLE OF CONTENTS
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TABLE OF CONTENTS ...............................................................I
TABLES..................................................................................V
FIGURES................................................................................ VI
ABOUT THIS MANUAL............................................................VII
ABOUT THIS MANUAL............................................................VII
1. INTRODUCTION ................................................................. 1
1.1 PRODUCT OVERVIEW ...........................................................................................................................1
1.2 SPECIFICATIONS ...................................................................................................................................2
1.2.1 GENERAL SPECIFICATIONS.......................................................................................................................2
1.2.1.1 EMBEDDED FEATURES...........................................................................................................................3
1.2.1.2 AMBIENT AND INSTRUMENT CONDITION MEASUREMENTS..............................................................4
1.2.2 PISTON-CYLINDER MODULES....................................................................................................................5
1.2.2.1 PC-7100/7600............................................................................................................................................5
1.2.2.2 PC-7200.....................................................................................................................................................6
1.2.2.3 PC-7300.....................................................................................................................................................7
1.2.3 MASS SETS...................................................................................................................................................8
1.2.4 PRESSURE MEASUREMENTS....................................................................................................................8
1.2.4.1 PC-7100/7600............................................................................................................................................8
1.2.4.2 PC-7200.....................................................................................................................................................9
1.2.4.3 PC-7300...................................................................................................................................................10
1.3 TERMINAL AND PLATFORM FRONT AND REAR PANELS...............................................................11
1.3.1 TERMINAL FRONT AND REAR PANELS ..................................................................................................11
1.3.1.1 PG TERMINAL FRONT PANEL...............................................................................................................11
1.3.1.2 PG TERMINAL REAR PANEL.................................................................................................................12
1.3.2 PLATFORM REAR PANELS.......................................................................................................................12
2. INSTALLATION ................................................................ 13
2.1 UNPACKING AND INSPECTION..........................................................................................................13
2.1.1 REMOVING FROM PACKAGING................................................................................................................13
2.1.1.1 PLATFORM..............................................................................................................................................13
2.1.1.2 MASS SET...............................................................................................................................................14
2.1.1.3 PISTON-CYLINDER MODULE(S)............................................................................................................14
2.1.2 INSPECTING CONTENTS...........................................................................................................................14
2.1.2.1 PLATFORM..............................................................................................................................................14
2.1.2.2 MASS SET...............................................................................................................................................19
2.1.2.3 PISTON-CYLINDER MODULE(S)............................................................................................................21
2.2 SITE REQUIREMENTS..........................................................................................................................22
2.3 SETUP ...................................................................................................................................................23
2.3.1 PREPARING FOR OPERATION.................................................................................................................23
2.3.1.1 SETTING UP THE PLATFORM...............................................................................................................23
2.3.1.2 SYSTEM PRESSURE INTERCONNECTIONS........................................................................................24
2.3.1.3 SETTING UP THE MASS SET.................................................................................................................24
2.3.2 INSTALLING A PISTON-CYLINDER MODULE INTO THE PLATFORM....................................................25
2.3.3 SWITCHING A PG7202 BETWEEN GAS OPERATION AND OIL OPERATION .......................................27
Page I © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
2.4 POWER UP AND VERIFICATION.........................................................................................................28
2.4.1 POWER UP..................................................................................................................................................28
2.4.2 CHECK THAT ON-BOARD PISTON-CYLINDER MODULE AND MASS SET INFORMATION
ARE CORRECT...........................................................................................................................................28
2.4.3 SET LOCAL GRAVITY VALUE ...................................................................................................................29
2.4.4 SETUP PRESSURE EQUATION VARIABLE INPUT SOURCES.....................................................29
2.4.5 CHECK PROPER OPERATION OF AMBIENT CONDITION MEASUREMENTS ......................................29
2.4.6 APPLY PRESSURE TO THE PISTON-CYLINDER MODULE....................................................................30
2.4.7 CHECK PROPER BEHAVIOR OF MOTORIZED PISTON ROTATION (IF PRESENT)..............................30
2.4.8 CHECK PROPER OPERATION OF PISTON BEHAVIOR MEASUREMENTS...........................................31
2.4.8.1 VERIFY VACUUM REFERENCE (PG7601 ONLY).................................................................................31
2.4.9 CHECK AUTOMATED PRESSURE GENERATION (IF PRESENT) ....................................................32
2.4.10 CHECK/SET SECURITY LEVEL.................................................................................................................32
2.4.11 ADDITIONAL PRECAUTIONS TO TAKE BEFORE MAKING PRESSURE MEASUREMENTS................32
2.5 SHORT TERM STORAGE.....................................................................................................................33
3. GENERAL OPERATION ..................................................... 35
3.1 FUNDAMENTAL OPERATING PRINCIPLES .......................................................................................35
3.1.1 GAS OPERATED, LIQUID LUBRICATED PISTON-CYLINDER OPERATING PRINCIPLE
(PG7202) ....................................................................................................................................................36
3.2 KEYPAD LAYOUT AND PROTOCOL...................................................................................................37
3.3 SOUNDS................................................................................................................................................38
3.4 PRESSURE READY/NOT READY INDICATION...................................................................................38
3.4.1 PISTON POSITION READY/NOT READY..................................................................................................39
3.4.2 PISTON ROTATION READY/NOT READY.................................................................................................39
3.4.3 VACUUM REFERENCE READY/NOT READY (PG7601 ONLY) .....................................................40
3.5 PISTON POSITION................................................................................................................................41
3.6 MASS LOADING PROTOCOL..............................................................................................................42
3.7 MAIN RUN SCREEN..............................................................................................................................45
3.8 GENERAL FUNCTION/MENU FLOW CHART......................................................................................46
3.9 DIRECT FUNCTION KEYS....................................................................................................................47
3.9.1 DIRECT FUNCTION KEYS SUMMARY......................................................................................................47
3.9.2 [P-C].............................................................................................................................................................48
3.9.3 [UNIT]...........................................................................................................................................................49
3.9.3.1 CUSTOMIZING PRESSURE UNITS AVAILABLE UNDER THE UNIT FUNCTION ................................51
3.9.4 [MODE] ........................................................................................................................................................52
3.9.4.1 DIFFERENTIAL MEASUREMENT MODE (PG7601 ONLY) ........................................................54
3.9.4.2 HIGH LINE DIFFERENTIAL MEASUREMENT MODE (PG7102 AND PG7202 ONLY)..........................61
3.9.5 [SYSTEM] ....................................................................................................................................................73
3.9.5.1 FIRST SYSTEM RUN SCREEN...............................................................................................................74
3.9.5.2 SECOND SYSTEM RUN SCREEN..........................................................................................................75
3.9.6 [AMBIENT]...................................................................................................................................................76
3.9.7 [HEAD].........................................................................................................................................................77
3.9.8 [ROTATE] (OPTIONAL ON PG7102, PG7202 AND PG7302)....................................................................79
3.9.9 [GEN] (OPTIONAL)......................................................................................................................................80
3.9.10 [RES]............................................................................................................................................................81
3.9.11 [ENTER] FROM RUN SCREEN...................................................................................................................82
3.9.11.1 [ENTER] IN PRESSURE TO MASS MODE.............................................................................................83
3.9.11.2 [ENT] IN MASS TO PRESSURE MODE..................................................................................................85
3.9.12 [P OR M] ......................................................................................................................................................86
3.9.13 [ ] .............................................................................................................................................................86
3.10 [SETUP] MENU......................................................................................................................................87
3.10.1 <1SELECT>.................................................................................................................................................89
3.10.2 <2VIEW>......................................................................................................................................................89
3.10.3 <3EDIT>.......................................................................................................................................................90
3.11 [SPECIAL] MENU..................................................................................................................................92
3.11.1 <1PC/MS>....................................................................................................................................................93
3.11.1.1 CREATE PISTON-CYLINDER MODULE.................................................................................................94
3.11.1.2 EDIT PISTON-CYLINDER MODULE INFORMATION.............................................................................97
3.11.1.3 VIEW PISTON-CYLINDER MODULE......................................................................................................97
3.11.1.4 DELETE PISTON-CYLINDER MODULE .................................................................................................98
3.11.1.5 SELECT THE ACTIVE PISTON-CYLINDER MODULE...........................................................................98
3.11.1.6 ADD MASS SET.......................................................................................................................................98
3.11.1.7 EDIT MASS SET....................................................................................................................................102
3.11.1.8 VIEW MASS SET...................................................................................................................................103
© 1998-2002 DH Instruments, Inc. Page II
TABLE OF CONTENTS
3.11.1.9 DELETE MASS SET ..............................................................................................................................103
3.11.1.10 SELECT MASS SET..............................................................................................................................103
3.11.1.11 ADD MASS LOADING BELL..................................................................................................................103
3.11.1.12 EDIT MASS LOADING BELL INFORMATION.......................................................................................105
3.11.1.13 VIEW MASS LOADING BELL................................................................................................................105
3.11.1.14 DELETE MASS LOADING BELL ...........................................................................................................105
3.11.1.15 SELECT MASS LOADING BELL ...........................................................................................................106
3.11.2 <2PRESU>.................................................................................................................................................106
3.11.3 <3HEAD>...................................................................................................................................................106
3.11.3.1 <3HEAD>, <1FLUID>.............................................................................................................................107
3.11.3.2 <3HEAD>, <2UNIT>...............................................................................................................................107
3.11.3.3 <3HEAD>, <3ATM> ...............................................................................................................................108
3.11.3.4 <3HEAD>, <4PISTON>..........................................................................................................................108
3.11.4 <4PREFS> .................................................................................................................................................109
3.11.4.1 <4PREFS>, <1SCRSVR>......................................................................................................................109
3.11.4.2 <4PREFS>, <2SOUND>........................................................................................................................109
3.11.4.3 <4PREFS>, <3TIME> ............................................................................................................................110
3.11.4.4 <4PREFS>, <4ID> .................................................................................................................................110
3.11.5 <5REMOTE>..............................................................................................................................................111
3.11.5.1 COM1, COM2 AND COM3 (RS232) ......................................................................................................111
3.11.5.2 IEEE-488................................................................................................................................................112
3.11.5.3 RS232 SELF TEST ................................................................................................................................112
3.11.5.4 EXTERNAL BAROMETER (RPM) COMMUNICATIONS (COM2).........................................................113
3.11.6 <6GL> ........................................................................................................................................................115
3.11.7 <7CAL>......................................................................................................................................................115
3.11.8 <8LEVEL>..................................................................................................................................................115
3.11.8.1 SECURITY LEVELS...............................................................................................................................116
3.11.9 <9RESET> .................................................................................................................................................119
3.11.9.1 <9RESET>, <1SETS>............................................................................................................................119
3.11.9.2 <9RESET>, <2UNITS> ..........................................................................................................................120
3.11.9.3 <9RESET>, <3COM>.............................................................................................................................120
3.11.9.4 <9RESET>, <4CAL>..............................................................................................................................120
3.11.9.5 <9RESET>, <5SETUPS>.......................................................................................................................121
3.11.9.6 <9RESET>, <6ALL>...............................................................................................................................121
4. REMOTE OPERATION ......................................................123
4.1 OVERVIEW..........................................................................................................................................123
4.2 INTERFACING.....................................................................................................................................123
4.2.1 RS232 INTERFACE...................................................................................................................................123
4.2.1.1 COM1.....................................................................................................................................................123
4.2.1.2 COM2 AND COM3.................................................................................................................................124
4.2.2 IEEE-488 (GPIB)........................................................................................................................................124
4.3 COMMANDS........................................................................................................................................125
4.3.1 COMMAND SYNTAX.................................................................................................................................125
4.3.2 COMMAND SUMMARY.............................................................................................................................126
4.3.3 ERROR MESSAGES.................................................................................................................................128
4.3.4 COMMAND DESCRIPTIONS.....................................................................................................................129
4.3.4.1 IEEE STD. 488.2 COMMON AND STATUS COMMANDS .....................................................129
4.3.4.2 PG7000 COMMANDS............................................................................................................................131
4.4 STATUS SYSTEM ...............................................................................................................................152
4.4.1 STATUS REPORTING SYSTEM...............................................................................................................152
4.4.1.1 STATUS BYTE REGISTER....................................................................................................................153
4.4.1.2 STANDARD EVENT REGISTER...........................................................................................................154
4.5 HIGH LINE DIFFERENTIAL MODE PROGRAMMING EXAMPLES ...................................................155
4.5.1 RECOMMENDED SEQUENCE FOR A HOST PROGRAM TO REMOTELY SET A NEW
HIGH LINE PRESSURE AND ENABLE HIGH LINE DIFFERENTIAL MODE ..........................................155
4.5.2 RECOMMENDED SEQUENCE FOR A HOST PROGRAM TO REMOTELY ENABLE
HIGH LINE DIFFERENTIAL MODE USING THE LAST LINE PRESSURE SETTING.............................157
Page III © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
5. MAINTENANCE, ADJUSTMENTS AND CALIBRATION ........... 159
5.1 INTRODUCTION..................................................................................................................................159
5.2 PLATFORM .........................................................................................................................................160
5.2.1 CALIBRATION/ADJUSTMENT OF ON-BOARD MEASUREMENT FUNCTIONS....................................160
5.2.1.1 PRINCIPLES..........................................................................................................................................160
5.2.1.2 BAROMETRIC PRESSURE SENSOR...................................................................................................161
5.2.1.3 AMBIENT TEMPERATURE SENSOR...................................................................................................161
5.2.1.4 RELATIVE HUMIDITY SENSOR............................................................................................................162
5.2.1.5 PI S T O N - C Y L I N D E R M O D U L E T E M P E R A T U R E S E N S O R ..................................................... 162
5.2.1.6 REFERENCE VACUUM GAUGE (PG7601 ONLY)...............................................................................164
5.2.2 PISTON POSITION DETECTION ADJUSTMENT.....................................................................................165
5.2.3 EMPTYING OIL RUN-OFF TRAY (PG7202 AND PG7302 ONLY).................................................165
5.2.4 PURGE MOUNTING POST LIQUID RUN OFF (PG7202 ONLY) ..............................................166
5.2.5 DRIVE BELT REPLACEMENT..................................................................................................................166
5.3 PISTON-CYLINDER MODULES..........................................................................................................167
5.3.1 DISASSEMBLY, CLEANING AND MAINTENANCE.................................................................................167
5.3.2 DISASSEMBLY AND REASSEMBLY.......................................................................................................168
5.3.2.1 DISASSEMBLY AND REASSEMBLY OF GAS OPERATED, GAS LUBRICATED
PISTON-CYLINDER MODULES (PC-7100/7600).......................................................................168
5.3.2.2 DISASSEMBLY AND REASSEMBLY OF GAS OPERATED, LIQUID LUBRICATED PISTON-CYLINDER
MODULES (PC-7200)............................................................................................................................172
5.3.2.3 DISASSEMBLY AND REASSEMBLY OF OIL OPERATED, OIL LUBRICATED
PISTON-CYLINDER MODULES (PC-7300) ..........................................................................................174
5.3.3 FILLING OR EMPTYING GAS OPERATED, LIQUID LUBRICATED PISTON-CYLINDER
MODULE RESERVOIR WITH LIQUID ......................................................................................................176
5.3.4 CLEANING PISTON-CYLINDERS.............................................................................................................177
5.3.5 RECALIBRATION......................................................................................................................................179
5.3.5.1 UPDATING PISTON-CYLINDER MODULE FILES................................................................................179
5.4 MASS SETS.........................................................................................................................................179
5.4.1 CLEANING.................................................................................................................................................179
5.4.2 RECALIBRATION......................................................................................................................................179
5.4.2.1 UPDATING ON-BOARD MASS SET FILES..........................................................................................179
5.5 RELOADING EMBEDDED SOFTWARE INTO PG7000 FLASH MEMORY........................................180
5.6 DISASSEMBLY AND REASSEMBLY OF PG7000.............................................................................180
5.6.1 PLATFORM................................................................................................................................................180
5.6.2 TERMINAL.................................................................................................................................................180
6. TROUBLESHOOTING .......................................................181
6.1 OVERVIEW..........................................................................................................................................181
7. APPENDIX ...................................................................... 183
7.1 CONVERSION OF NUMERICAL VALUES..........................................................................................183
7.1.1 PRESSURE................................................................................................................................................183
7.2 DEFINED PRESSURE CALCULATIONS............................................................................................183
7.2.1 PG7102, PG7202 AND PG7302................................................................................................................185
7.2.2 PG7601 ......................................................................................................................................................186
7.2.3 FLUID HEADS ...........................................................................................................................................187
7.2.3.1 FLUID HEAD COMPONENTS...............................................................................................................187
7.2.3.2 OVERALL FLUID HEAD CORRECTION...............................................................................................188
7.3 GLOSSARY.........................................................................................................................................189
7.4 WARRANTY STATEMENT..................................................................................................................191
© 1998-2002 DH Instruments, Inc. Page IV
TABLES AND FIGURES
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Table 1. PG7102 Parts List........................................................................................................................15
Table 2. PG7202 Parts List........................................................................................................................16
Table 3. PG7302 Parts List........................................................................................................................17
Table 4. PG7601 Parts List........................................................................................................................18
Table 5. Mass Parts List (excluding 80 and 100 kg)..................................................................................19
Table 6. Mass Parts List (80 and 100 kg)..................................................................................................19
Table 7. Mass Set Definitions ....................................................................................................................20
Table 8. Mass Set Compatibility ................................................................................................................20
Table 9. PC-7100/7600 Piston-Cylinder Modules Parts List .....................................................................21
Table 10. PC-7200 Piston-Cylinder Modules Parts List ............................................................................21
Table 11. PC-7300 Piston-Cylinder Modules Parts List ...........................................................................21
Table 12. Summary of PG7000 Direct Function Key Operations..............................................................47
Table 13. Pressure Units of Measure Available.........................................................................................51
Table 14. Valve Settings for Setting Differential Mode Static Pressure.....................................................57
Table 15. Valve Settings to Apply PG7000 Pressure to the RPM for Differential Mode Offsetting...........57
Table 16. Valve Settings for Operating in Differential Mode......................................................................59
Table 17. SETUP File Choices, Factory Preferred Choice and Normal Value..........................................88
Table 18. COM1, COM2 and COM3 Available Settings.......................................................................... 111
Table 19. Security Levels - Functions NOT Executed Per Function/Level.............................................. 117
Table 20. COM1 DB-9F Pin Designation.................................................................................................124
Table 21. COM2 and COM3 DB-9M Pin Designation .............................................................................124
Table 22. Command Summary................................................................................................................126
Table 23. Error Messages........................................................................................................................128
Table 24. Status Byte Register ................................................................................................................153
Table 25. Standard Event Register..........................................................................................................154
Table 26. Mounting Post Wire Colors, Description and Location............................................................164
Table 27. PG7000 Troubleshooting Checklist.........................................................................................181
Table 28. Pressure Unit of Measure Conversions...................................................................................183
Table 29. PG7000 Defined Pressure Calculation Variables....................................................................184
Table 30. DHI Authorized Service Providers ...........................................................................................191
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Page V © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
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Figure 1. PG Terminal Front Panel............................................................................................................ 11
Figure 2. PG Terminal Rear Panel.............................................................................................................12
Figure 3. PG Platform Rear Panel.............................................................................................................12
Figure 4. Piston-Cylinder Module Installation............................................................................................26
Figure 5. Piston Gauge Operating Principle..............................................................................................35
Figure 6. Gas Operated, Liquid Lubricated Piston-Cylinder (PC-7200) Operating Principle ...................37
Figure 7. PG7000 Keypad Layout..............................................................................................................37
Figure 8. Piston Stroke and Zones ............................................................................................................41
Figure 9. Run Screen Flow Chart ..............................................................................................................46
Figure 10. Differential Mode Controller Schematic....................................................................................55
Figure 11. High Line Differential Mode Schematic ....................................................................................64
Figure 12. Status Byte Register...............................................................................................................153
Figure 13. PG7202 Mounting Post Drain.................................................................................................166
Figure 14. 10 kPa/kg Gas Piston-Cylinder Module (Expanded View).....................................................169
Figure 15. 10 kPa/kg Piston Insertion Tool..............................................................................................170
Figure 16. Gas Piston-Cylinder Module Sleeve Nut Tool........................................................................170
Figure 17. 50 and 200 kPa/kg Gas Piston-Cylinder Modules (Expanded View).....................................171
Figure 18. Gas Operated, Liquid Lubricated Piston-Cylinder Module (Expanded View) .......................173
Figure 19. Oil Piston-Cylinder Module (Expanded View) ........................................................................175
Figure 20. Filling Gas Operated, Liquid Lubricated Piston-Cylinder Module Reservoir (PC-7200).......177
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© 1998-2002 DH Instruments, Inc. Page VI
ABOUT THIS MANUAL
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This manual provides the user with the information necessary to operate various PG7000 Piston Gauges. It also includes a great deal of additional information provided to help you optimize PG7000 use and take full advantage of its many features and functions.
This manual covers four PG7000 models: PG7102, PG7202, PG7302 and PG7601. The four models have many features and characteristics in common as well as individual differences. When discussing features that are common to all four models, they are referred to collectively as PG7000. When providing information pertaining to a specific model, that model is referred to by its specific model number.
Before using the manual, take a moment to familiarize yourself with the Table of Contents structure. All first time PG7000 users should read Sections 1 and 2. Section 3 provides a comprehensive description of general PG7000 operating principles. Section 4 covers remote communication with an external computer. Section 5 provides maintenance and calibration information. Section 6 is a quick troubleshooting guide. Use the information in Section 6 to troubleshoot unexpected PG7000 behavior based on the symptoms of that behavior.
Certain words and expressions have specific meaning as they pertain to PG7000s. The Glossary (see Section 7) is useful as a quick reference for the definition of specific words and expressions as they are used in this manual.
FOR THOSE OF YOU WHO “DON’T READ MANUALS”, GO DIRECTLY TO SECTION 2.3 TO SET UP
YOUR PG7000. THEN GO TO SECTION 2.4. THIS WILL GET YOU RUNNING QUICKLY WITH MINIMAL RISK OF CAUSING DAMAGE TO YOURSELF OR YOUR PG7000. THEN… WHEN YOU HAVE QUESTIONS OR START TO WONDER ABOUT ALL THE GREAT FEATURES YOU MIGHT BE MISSING, GET INTO THE MANUAL!
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Manual Conventions
(CAUTION) is used throughout the manual to identify user warnings and cautions.
(NOTE) is used throughout the manual to identify operating and applications advice and
additional explanations.
[ ] indicates direct function keys (e.g., [RANGE]).
< > indicates PG7000 screen displays (e.g., <1yes>)
Page VII © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
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© 1998-2002 DH Instruments, Inc. Page VIII
1. INTRODUCTION
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1.1 PRODUCT OVERVIEW
PG7000 Piston Gauges are reference level pressure standards that operate on the piston gauge principle. Pressure is defined by balancing it against the force exerted by a known mass accelerated by gravity on the effective area of a piston-cylinder.
A PG7000 piston gauge consists of the PG7000 Platform, one or several piston-cylinder modules and a mass set. A PG7000 system also includes the means to generate and adjust pressures and to interconnect the system components and a device being calibrated or tested. The system may also include COMPASS test reports.
There are four PG7000 Platforms: Model PG7102, PG7202, PG7302 and PG7601. These have common PG7000 presentation and features. They are distinguished by their normal operating medium (oil or gas) and the capability to define pressures relative to a vacuum reference.
PG7102 - Gas operated with gas lubricated piston-cylinder modules (PC-7100/7600 modules)
- Maximum pressure is 11 MPa (1 600 psi)
- Does not support definition of pressure against a vacuum reference
®
software to assist in executing test sequences, acquiring test data and producing
PG7202 - Gas operated, liquid lubricated piston-cylinder modules (PC-7200 modules)
- Oil operated piston-cylinder modules (PC-7300 modules)
- Its maximum pressure is 110 MPa (16 000 psi) when operated with a PC-7200 module
- Its maximum pressure is 200 MPa (30 000 psi) when operated with a PC-7300 module
- Does not support definition of pressure against a vacuum reference
PG7302 - Oil operated (PC-7300 modules)
- Maximum pressure is 500 MPa (72 500 psi)
PG7601 - Gas operated, gas lubricated piston-cylinder modules (PC-7100/7600 modules)
- Maximum pressure is 11 MPa (1 600 psi)
- Supports definition of pressure against a vacuum reference
PG7000 platforms, piston-cylinder modules and mass sets are designed to maximize metrological performance and ease of operation. They include many features that enhance the fundamental precision and stability of pressure measurements as well as simplifying use and reducing the operator influence on the measurements. Extensive monitoring and controlling capability and advanced local and remote user interfaces are integrated into PG7000 Platforms.
Operator interaction with PG7000 and its extensive capabilities is accomplished through the display and keypad of the PG Terminal or from a computer via a standard RS232 or IEEE-488 interface.
Page 1 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
1.2 SPECIFICATIONS
1.2.1 GENERAL SPECIFICATIONS
Power Requirements Operating Temperature Range Weight
Instrument platform with no mass loaded.
PG7102 PG7202 PG7302 PG7601
PG Terminal
Dimensions
Instrument Platform
PG Terminal
Microprocessors
Instrument Platform
PG Terminal
Communication Ports
RS232
IEEE-488
Overall Pressure Ranges
Actual range depends on piston-cylinder and mass set selection
PG7102 Gauge: 5 kPa to 11 MPa (0.7 to 1 600 psi)
PG7202 Gauge: 100 kPa to 110 MPa (15 to 16 000 psi)
85 to 264 VAC, 50/60 Hz, 22 VA max. consumption. 15 to 35 °C
13 kg (29 lb) 13 kg (29 lb) 13 kg (29 lb) 17 kg (37 lb)
1.4 kg (3 lb)
36 cm H x 40 cm W x 35 cm D (14.5 in. x 15.8 in. x 13.8 in.) (Height: Top of mounting post with piston-cylinder module installed
for PG7102/PG7202/PG7302; top of bell jar for PG7601.) 12 cm H x 15 cm W x 20 cm D (4.7 in. H x 5.9 in. W x 7.9 in. D)
Motorola 68302 Hitachi 64180
COM1: Host computer COM2: External barometer and pass through communications
COM3: Automated pressure generator/controller Host computer
Absolute: 105 kPa to 11 MPa (15 to 1 600 psi) Differential: DP + static pressure < 11 MPa (1 600 psi)
Absolute: 200 kPa to 110 MPa (30 to 16 000 psi) Differential: DP + static pressure < 110 MPa (16 000 psi)
Operating Media
Maximum Mass Load
© 1998-2002 DH Instruments, Inc. Page 2
PC-7200 can be operated in oil up to 200 MPa (30 000 psi)
PG7302 Gauge: 20 kPa to 500 MPa (3 to 75 000 psi)
PG7601 Gauge: 5 kPa to 7 MPa (0.7 to 1 000 psi)
PG7102 PG7202
PG7302 PG7601
PG7102 PG7102
PG7302 PG7601
Absolute: 120 kPa to 500 MPa (20 to 75 000 psi)
Absolute: 5 kPa to 7 MPa (0.7 to 1 000 psi) Differential: 90 to 350 kPa (-12 to 50 psi) at 15 to 200 kPaa (2 to 30 psia) static pressure
Gas: air, helium, nitrogen Gas: any non-corrosive
Oil: Di2-EthylHexyl Sebacate (synthetic oil) Oil: Di2-EthylHexyl Sebacate (synthetic oil) Gas: air, helium, nitrogen
100 kg, while not exceeding 11 MPa (1 600 psi) 100 kg, while not exceeding 110 MPa (16 000 psi) when operated
with PC-7200 piston-cylinder modules or 200 MPa (30 000 psi) when operated with PC-7300 piston-cylinder modules
100 kg 35 kg
when used with PC-7300 oil operated piston-cylinders.
1. INTRODUCTION
Pressure Connections
PG7102 PG7202
PG7302 PG7601
CE Conformance
Test port: DH200 Test port: DH500
Drain port: DH500 Test port: DH500 Test port: DH200
Bell Jar Vent Port: DH200 Vacuum Reference Pump Down Port: KF25
DH200 and DH500 are gland and collar type fittings for
1/4 in. (6 mm) coned and left hand threaded tubes.
DH200 is equivalent to AE SF250C, HIP LF4, etc.
DH500 is equivalent to AE F250C, HIP HF4, etc.
Available, must be specified.
1.2.1.1 EMBEDDED FEATURES
Local control with 2 x 20 vacuum fluorescent display and 4 x 4 function driven keypad.
Real time (1 second update rate) display and measurement of ambient (pressure, temperature, humidity) and instrument (piston-cylinder temperature, piston position, piston drop rate, piston rotation rate, piston rotation decay rate, reference vacuum) conditions.
Real time (1 second update rate) mass-to-pressure and pressure-to-mass calculations taking into consideration all environmental and operational variables.
Full gas and liquid fluid head corrections including DUT head correction and piston position head correction.
Adjustable mass loading resolution (0.01 g to 0.1 kg).
Audible prompts of instrument status (piston movement, Ready/Not Ready indication)
with override capability.
Interfacing and automatic exploitation of any external barometer (RS232).
Automated differential mode to define low differential pressures at various
static pressures between vacuum and two atmospheres.
Automated high line differential mode to define differential pressure at high line pressure.
Storage and one step activation of metrological data on up to 18 piston-cylinder modules, (3) mass sets and (3) mass loading bells.
Continuous pressure Ready/Not Ready indication based on measured conditions.
Motorized, intelligent piston drive system based measured rotation rate with operator alert and manual override (motorization optional on PG7102 and PG7302).
Built-in drivers for automated pressure control components and piston floating with override capability.
Full RS232 and IEEE-488 communications with multi-level commands to set and read all instrument functions.
Page 3 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
1.2.1.2 AMBIENT AND INSTRUMENT CONDITION
MEASUREMENTS
Temperature
Range
Resolution
Measurement Uncertainty
Barometric Pressure with Internal Sensor
Range
Resolution
Measurement Uncertainty
Relative Humidity
Range
Resolution
Measurement Uncertainty
Piston Position
Range
Resolution
Measurement Uncertainty
Piston Rotation
(Rate and deceleration)
Range
Resolution
Ambient 0 to 40
0.1 0.01 ± 1 ± 0.1
70 to 110 kPa 10 Pa ± 140 Pa Barometric pressure can also be read automatically with any
RS232 device such as a DHI RPM.
5 to 95 % RH 1 % RH
± 10 % RH
± 4.5 mm
0.1 mm ± 0.2 mm
2 to 99 rpm 1 rpm
Piston Cylinder Module
o
C 0 to 40 oC
Vacuum
(PG7601 only)
Range
Resolution
Measurement Uncertainty
0 to 20 Pa
0.01 Pa ± 0.1 Pa or 10 % of reading, whichever is greater
© 1998-2002 DH Instruments, Inc. Page 4
1. INTRODUCTION
1.2.2 PISTON-CYLINDER MODULES
All piston-cylinders are integrated modules including mounting hardware delivered in individual shipping and storage bullet cases.
1.2.2.1 PC-7100/7600
Gas operated, gas lubricated piston-cylinder characteristics.
PC-7100/7600-10
Operation
Piston Material
Cylinder Material
Nominal Diameter
Nominal Area
Mounting System
PC-7100/7600-50
Operation
Piston Material
Cylinder Material
Nominal Diameter
Nominal Area
Mounting system
PC-7100/7600-200
Operation
Piston Material
Cylinder Material
Nominal Diameter
Nominal Area
Mounting System
Gas operated, gas lubricated Ceramic (tungsten carbide available, higher mass) Tungsten carbide 35 mm 1 000 mm Simple free deformation
Gas operated, gas lubricated Tungsten carbide Tungsten carbide 16 mm 200 mm Negative free deformation
Gas operated, gas lubricated Tungsten Carbide Tungsten carbide 8 mm 50 mm Negative free deformation
2
2
2
Page 5 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
1.2.2.2 PC-7200
Gas operated, liquid lubricated piston-cylinder module characteristics.
Though not recommended for day to day operation, PC-7200 modules can
also be filled completely with oil and operated with oil as the test medium (see Section 2.3.3).
PC-7200-100
Operation
Lubricating Liquid
Piston Material
Cylinder Material
Nominal Diameter
Nominal Area
Mounting System
PC-7200-200
Operation
Lubricating Liquid
Piston Material
Cylinder Material
Nominal Diameter
Nominal Area
Mounting System
PC-7200-500
Operation
Lubricating Liquid
Piston Material
Cylinder Material
Nominal Diameter
Nominal Area
Mounting System
PC-7200-1
Operation
Lubricating Liquid
Piston Material
Cylinder Material
Nominal Diameter
Nominal Area
Mounting System
PC-7200-2
Operation
Lubricating Liquid
Piston Material
Cylinder Material
Nominal Diameter
Nominal Area
Mounting System
Gas operated, liquid lubricated Synturion 6 (Krytox
®
optional) Tungsten carbide Tungsten carbide
11.2 mm
98.1 mm
2
Negative free deformation
Gas operated, liquid lubricated Synturion 6 (Krytox
®
optional) Tungsten carbide Tungsten carbide
7.9 mm
49.0 mm
2
Negative free deformation
Gas operated, liquid lubricated Di-2-ethylhexyl Sebacate (Krytox Tungsten carbide Tungsten carbide
5.0 mm
19.6 mm
2
Negative free deformation
Gas operated, liquid lubricated Di-2-ethylhexyl Sebacate (Krytox Tungsten carbide Tungsten carbide
3.5 mm
2
9.8 mm Negative free deformation
Gas operated, liquid lubricated Di-2-ethylhexyl Sebacate (Krytox Tungsten carbide Tungsten carbide
2.5 mm
2
4.9 mm Negative free deformation
®
optional)
®
optional)
®
optional)
© 1998-2002 DH Instruments, Inc. Page 6
1. INTRODUCTION
1.2.2.3 PC-7300
PC-7300 modules PC-7300-1, -2 and -5 may also be used in a PG7202 platform.
Oil operated, oil lubricated piston-cylinder module characteristics.
PC-7300-100
Operation
Piston and Cylinder Material
Nominal Diameter
Nominal Area
Mounting System
PC-7300-200
Operation
Piston Material
Nominal Diameter
Nominal Area
Mounting System
PC-7300-500
Operation
Piston Material
Nominal Diameter
Nominal Area
Mounting System
PC-7300-1
Operation
Piston Material
Nominal Diameter
Nominal Area
Mounting System
PC-7300-2
Operation
Piston Material
Nominal Diameter
Nominal Area
Mounting System
PC-7300-5
Operation
Piston Material
Nominal Diameter
Nominal Area
Mounting System
Oil operated, oil lubricated Tungsten carbide
11.2 mm
98.1 mm
2
Simple free deformation
Oil operated, oil lubricated Tungsten carbide
7.9 mm
49.0 mm
2
Simple free deformation
Oil operated, oil lubricated Tungsten carbide
5.0 mm
19.6 mm
2
Simple free deformation
Oil operated, oil lubricated Tungsten carbide
3.5 mm
2
9.8 mm Simple free deformation
Oil operated, oil lubricated Tungsten carbide
2.5 mm
2
4.9 mm Simple free deformation
Oil operated, oil lubricated Tungsten carbide
2.0 mm
2
2.0 mm Simple free deformation
Page 7 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
1.2.3 MASS SETS
Masses > 50g
Material
Finish
Adjustment Tolerance
Uncertainty of Measured Values
Masses < 50g
304L non-magnetic stainless steel Electropolished
± 20 ppm of nominal value ± 5 ppm or 1 mg, whichever is greater
Conform to NIST S1
Masses designated “tare” are delivered without reported measured values and are intended
only for use on the “tare” PG7000 in high line differential pressure measurement mode.
1.2.4 PRESSURE MEASUREMENTS
1.2.4.1 PC-7100/7600
For uncertainty in piston-cylinder effective area and typical measurement
uncertainty in pressure defined by the piston gauge, see the piston-cylinder calibration report and DHI Technical Note 7920TN01.
All masses are delivered in molded, reusable, transit cases with custom inserts.
PC-7100/7600-10
Sensitivity
Reproducibility
Typical Drop Rate (35 kg)
1
0.02 Pa + 0.5 ppm
2
± 2 ppm
0.2 mm/min
PC-7100/7600-50
Sensitivity
Reproducibility
Typical Drop Rate (35 kg)
PC-7100/7600-200
Sensitivity
Reproducibility
Typical Drop Rate (35 kg)
1
0.1 Pa + 0.5 ppm
2
± 3 ppm
0.5 mm/min
1
0.4 Pa + 0.5 ppm
2
± 5 ppm
1.0 mm/min
Piston-cylinder modules designated “tare” are delivered without reported
values and are intended only for use on the “tare” PG7000 in high line differential pressure measurement mode.
1 Sensitivity: The smallest variation in input detectable in output. 2 Reproducibility: Combined long term stability of piston-cylinder effective area and masses.
© 1998-2002 DH Instruments, Inc. Page 8
1. INTRODUCTION
1.2.4.2 PC-7200
For uncertainty in piston-cylinder effective area and typical measurement
uncertainty in pressure defined by the piston gauge, see the piston-cylinder calibration report and DHI Technical Note 7920TN01.
PC-7200-100
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
1
2 Pa + 1 ppm
2
± 5 ppm
0.10 mm/min
PC-7200-200
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
PC-7200-500
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
PC-7200-1
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
PC-7200-2
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
1 Sensitivity: The smallest variation in input detectable in output. 2 Reproducibility: Combined long term stability of piston-cylinder effective area and masses.
1
4 Pa + 1 ppm
2
± 5 ppm
0.15 mm/min
1
10 Pa + 1 ppm
2
± 5 ppm
0.20 mm/min
1
20 Pa + 1 ppm
2
± 5 ppm
0.25 mm/min
1
40 Pa + 1 ppm
2
± 5 ppm
0.50 mm/min
Page 9 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
1.2.4.3 PC-7300
For uncertainty in piston-cylinder effective area and typical measurement
uncertainty in pressure defined by the piston gauge, see the piston-cylinder calibration report and DHI Technical Note 7920TN01.
PC-7300-100
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
1
2 Pa + 1 ppm
2
± 5 ppm
0.02 mm/min
PC-7300-200
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
PC-7300-500
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
PC-7300-1
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
PC-7300-2
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
PC-7300-5
Sensitivity
Reproducibility
Typical Drop Rate (50 kg)
1 Sensitivity: The smallest variation in input detectable in output. 2 Reproducibility: Combined long term stability of piston-cylinder effective area and masses.
1
4 Pa + 1 ppm
2
± 5 ppm
0.04 mm/min
1
10 Pa + 1 ppm
2
± 5 ppm
0.10 mm/min
1
20 Pa + 1 ppm
2
± 5 ppm
0.20 mm/min
1
40 Pa + 1 ppm
2
± 5 ppm
0.40 mm/min
1
100 Pa + 1 ppm
2
± 5 ppm
1.00 mm/min
© 1998-2002 DH Instruments, Inc. Page 10
1. INTRODUCTION
1.3 TERMINAL AND PLATFORM FRONT AND REAR PANELS
1.3.1 TERMINAL FRONT AND REAR PANELS
1.3.1.1 PG TERMINAL FRONT PANEL
The front panel assembly provides a 2 x 20 vacuum fluorescent display and a 4 x 4 membrane keypad for local user interface. The terminal front panel assembly is the same for all PG7000 models (i.e., PG7102, PG7202, PG7302, PG7601).
1. Fluorescent display
2. Keypad
Figure 1. PG Terminal Front Panel
Page 11 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
1.3.1.2 PG TERMINAL REAR PANEL
The rear panel assembly provides the communications connection to the PG7000 Platform and the power connection module. The terminal rear panel assembly is the same for all PG7000 models.
Figure 2. PG Terminal Rear Panel
1. Power Switch
2. Fuse (25-pin)
3. Power Receptacle
4. Connector for Cable to PG7000
5. Cooling Fan
1.3.2 PLATFORM REAR PANELS
The PG7000 Platform rear panels provide the connection to the PG Terminal, remote communication connections and pressure connection ports. The rear panels of all PG7000 models are identical except for the pressure connections (see Figure 3, # 6).
1. COM2 (RS232) - External Barometer and Pass Through Communications
2. COM3 (RS232) - Automated Pressure Generation/Control Component
3. COM1 (RS232) - Remote Host Communications
4. Ambient Temperature Sensor
5. IEEE-488 - Remote Host Communications
6. Ambient Relative Humidity Sensor
7. Pressure Ports:
PG7102 - TEST port: DH200
PG7202 - TEST and DRAIN ports: DH500 PG7302 - TEST port: DH500 PG7601 - TEST and VACUUM vent ports: DH200
Vacuum pull down port on front left side: KF25
8. PG7000 Terminal Port
Figure 3. PG Platform Rear Panel
© 1998-2002 DH Instruments, Inc. Page 12
2. INSTALLATION
22..
I
NNSSTTAALLLLAATTIIOON
I
N
2.1 UNPACKING AND INSPECTION
2.1.1 REMOVING FROM PACKAGING
A typical PG7000 system includes the PG7000 Platform (see Section 2.1.1.1), a mass set, (see Section 2.1.1.2), one or more piston-cylinder modules (see Section 2.1.1.3) and other accessories (see the accessory Operation and Maintenance Manual or Instruction Sheet).
2.1.1.1 PLATFORM
The mass loading bell is a metrological element that is part of the mass set.
Like all of the masses, it is preferable not to handle it with bare hands. Protective gloves are provided in the accessory kit of each PG7000 Platform.
The PG7000 Platform is shipped in a reusable, molded shipping and storage case. Open the PG7000 shipping and storage case (it is the large, 66 cm x 53 cm
x 47 cm case).
Remove the PG Terminal and accessories from upper packing insert.
Inspect and inventory the accessories (see Section 2.1.2).
Remove the upper packing insert. Carefully lift the PG7000 Platform from its position in the lower packing
insert. Note the orientation so that the same orientation will be used when PG7000 is repacked.
Reinstall the upper packing insert into the shipping and storage case and
store in a safe place.
Page 13 ©1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
2.1.1.2 MASS SET
The stability over time of PG7000 pressure measurements is a function of
the stability of the masses loaded on the piston. Precautions should be taken in handling the masses to minimize influences that may change their mass. This includes always wearing protective gloves when handling the masses to avoid contaminating them with body oils and perspiration. Protective gloves are provided in the accessory kits of PG7000 Platforms.
The mass set accessories are shipped in a separate corrugated container. Open the corrugated container and inspect and inventory the accessories.
The PG7000 masses are shipped in reusable, molded shipping and storage cases. The PG7000 masses should be removed from their shipping cases and inventoried when actually setting up the PG7000 system.
2.1.1.3 PISTON-CYLINDER MODULE(S)
The piston-cylinder modules are shipped in PVC bullet cases that are packed in corrugated containers with custom foam inserts.
Open the corrugated containers and remove the piston-cylinder modules and accessories.
When reinstalling an oil (PC-7300) or liquid lubricated (PC-7200) piston-cylinder
module in its bullet case, be sure to empty out any liquid that may have collected in the hole in the bottom of the case. Excess liquid will not compress, making it difficult to fully close the case and could result in damaging it.
2.1.2 INSPECTING CONTENTS
Check that all items are present and have NO visible signs of damage. A parts list of items supplied is provided in Section 2.1.2.1 for PG7000, Section 2.1.2.2 for mass sets, and Section 2.1.2.3 for piston-cylinder modules.
2.1.2.1 PLATFORM
Each PG7000 Platform is delivered complete with accessories as listed by part number in Tables 1 through 4.
The bullet cases screw open by turning the lid counterclockwise.
© 1998-2002 DH Instruments, Inc. Page 14
2. INSTALLATION
Table 1. PG7102 Parts List
PG7102
P/N 401141
DESCRIPTION
Platform 401294 401294-CE 401293 401293-CE Mass Bell 401132 Bell Jar and Seal Terminal 401284 PG Terminal to Platform Cable Non-CE (DB25M - DB25F,
1.8 meters) CE (DB25M - DB25F,
1.5 meters) Power Cable 100770 (Black) 100770-CE (Gray) 100770 (Black) 100770-CE (Gray) Accessory Kit 401560 NIP, SS, DH200, 2.75 in. 100204 ADPT, SS, DH200 F x 2 NPT F 100299 O-ring, Buna 2-242 (2 ea.) 101976 Storage Cover, 7600 Type 102132 Allen Wrench, 2.5 mm 102257 Allen Wrench, 3 mm 102168 Allen Wrench, 5 mm 102262 Spanner Wrench (Metrological) 122568 Wrench, 5/8 in. Collar, SS, DH500 Krytox GPL205/6 0.5 oz. Gift Kit with Gloves 400511 Valve, Vacuum Relief Union, SS, 2P Valve, Toggle 2T,OGS2 Instruction Sheet,
PG7600 Vac Relief ADPT, DH200 M x 2T ADPT, SS, DH200M x 2T Frl, SS, Front, Gyr 2T Frl, SS, Rear, Gyr, 2T Nut, SS, Gyr, 2T
Documentation Calibration Report (PG Platform) Calibration Report (Mass Bell) Technical Data PG7000 Operation & Maintenance Manual Documentation CD
MOTORIZED
ROTATION
NON-CE
102227 102227
102227-CE 102227-CE
PG7102
P/N 401141-CE
MOTORIZED
ROTATION
CE
PG7102
P/N 401140
NON-MOTORIZED
ROTATION
NON-CE
102496
550100 550100 550101
550099 102987
PG7102
P/N 401140-CE
NON-MOTORIZED
ROTATION
CE
Page 15 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Table 2. PG7202 Parts List
PG7202
#401722
DESCRIPTION
Platform 401725 401725-CE 401724 401724-CE Mass Bell 401132 Bell Jar and Seal Terminal 401284 PG Terminal to Platform Cable Non-CE (DB25M - DB25F,
1.8 meters) CE (DB25M - DB25F,
1.5 meters) Power Cable 100770 (Black) 100770-CE (Gray) 100770 (Black) 100770-CE (Gray) Accessory Kit 401134 NIP, SS, DH200, 2.75 in. 100204 ADPT, SS, DH200 F x 2 NPT F 100299 O-ring, Buna 2-242 (2 ea.) 101976 Storage Cover, 7600 Type 102132 Allen Wrench, 2.5 mm 102257 Allen Wrench, 3 mm 102168 Allen Wrench, 5 mm 102262 Spanner Wrench (Metrological) 122568 Wrench, 5/8 in. 103044 Collar, SS, DH500 101201 Krytox GPL205/6 0.5 oz. Gift Kit with Gloves 400511 Valve, Vacuum Relief Union, SS, 2P Valve, Toggle 2T,OGS2 Instruction Sheet, PG7600
Vac Relief ADPT, DH200 M x 2T ADPT, SS, DH200M x 2T Frl, SS, Front, Gyr 2T Frl, SS, Rear, Gyr, 2T Nut, SS, Gyr, 2T Documentation
Calibration Report (PG) Calibration Report (Mass Bell) Technical Data PG7000 Operation & Maintenance Manual Documentation CD
MOTORIZED
ROTATION
NON-CE
102227 102227
102227-CE 102227-CE
PG7202
#401722-CE
MOTORIZED
ROTATION
CE
PG7202
#401721
NON-MOTORIZED
ROTATION
NON-CE
102496
550100 550100 550101 550099
102987
PG7202
#401721-CE
NON-MOTORIZED
ROTATION
CE
© 1998-2002 DH Instruments, Inc. Page 16
2. INSTALLATION
Table 3. PG7302 Parts List
PG7302
DESCRIPTION
Platform 401292 401292-CE 401291 401291-CE Mass Bell 401132 Bell Jar and Seal Terminal 401284 PG Terminal to Platform Cable Non-CE (DB25M -DB25F,
1.8 meters) CE (DB25M - DB25F,
1.5 meters) Power Cable 100770 (Black) 100770-CE (Gray) 100770 (Black) 100770-CE (Gray) Accessory Kit 401134 NIP, SS, DH200, 2.75 in. 100204 ADPT, SS, DH200 F x 2 NPT F 100299 O-ring, Buna 2-242 (2 ea.) 101976 Storage Cover, 7600 Type 102132 Allen Wrench, 2.5 mm 102257 Allen Wrench, 3 mm 102168 Allen Wrench, 5 mm 102262 Spanner Wrench (Metrological) 122568 Wrench, 5/8 in. 103044 Collar, SS, DH500 101201 Krytox GPL205/6 0.5 oz. Gift Kit with Gloves 400511 Valve, Vacuum Relief Union, SS, 2P Valve, Toggle 2T,OGS2 Instruction Sheet, PG7600
Vac Relief ADPT, DH200 M x 2T ADPT, SS, DH200M x 2T Frl, SS, Front, Gyr 2T Frl, SS, Rear, Gyr, 2T Nut, SS, Gyr, 2T Documentation
Calibration Report (PG) Calibration Report (Mass Bell) Technical Data PG7000 Operation & Maintenance Manual Documentation CD
P/N 401298
MOTORIZED
ROTATION
NON-CE
102227
PG7302
P/N 401298-CE
MOTORIZED
ROTATION
CE
102227
102227-CE 102227-CE
102496
550100 550100 550101 550099
102987
PG7302
P/N 401297
NON-MOTORIZED
ROTATION
NON-CE
PG7302
P/N 401297-CE
NON-MOTORIZED
ROTATION
CE
Page 17 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Table 4. PG7601 Parts List
PG7601
P/N 400480
DESCRIPTION
Platform 401290 401290-CE Mass Bell 400578 Bell Jar and Seal 122106 and 101546 Terminal 401284 PG Terminal to Platform Cable Non-CE (DB25M -DB25F,
1.8 meters) CE (DB25M - DB25F,
1.5 meters) Power Cable 100770 (Black) 100770-CE (Gray) Accessory Kit 400987 NIP, SS, DH200, 2.75 in. 100204 ADPT, SS, DH200 F x 2 NPT F 100299 O-ring, Buna 2-242 (2 ea.) 101976 Storage Cover, 7600 Type 102132 Allen Wrench, 2.5 mm 102257 Allen Wrench, 3 mm 102168 Allen Wrench, 5 mm 102262 Spanner Wrench (Metrological) 122568 Wrench, 5/8” Collar, SS, DH500 Krytox GPL205/6 .5 oz. Gift Kit with Gloves 400511 Valve, Vacuum Relief 401050 Union, SS, 2P 101980 Valve, Toggle 2T,OGS2 102119 Instruction Sheet, PG7600
Vac Relief ADPT, DH200 M x 2T 400518 ADPT, SS, DH200M x 2T 121692 Frl, SS, Front, Gyr 2T 100179 Frl, SS, Rear, Gyr, 2T 100181 Nut, SS, Gyr, 2T 100183 Documentation
Calibration Report (PG) Calibration Report (Mass Bell) Technical Data PG7000 Operation & Maintenance Manual Documentation CD
MOTORIZED
ROTATION
NON-CE
102227
102227-CE
102496
560002
550100 550100 550101 550099
102987
PG7601
P/N 400480-CE
MOTORIZED
ROTATION
CE
© 1998-2002 DH Instruments, Inc. Page 18
2. INSTALLATION
2.1.2.2 MASS SET
PG7000 mass sets are composed of different combinations of individual masses and accessories depending on the specific mass set ordered (see Tables 5, 6, 7).
Table 5. Mass Parts List (excluding 80 and 100 kg)
DESCRIPTION PART NO.
Mass Set Refer to Table 7 Reusable Molded Transit Case with Foam Inserts
35 kg set 40 kg set 45 kg set 55 kg set
Mass Set Tray and Spindle 123050 and 123051 Dust Covers 102814 and 102847 Calibration Report 550100
Table 6. Mass Parts List (80 and 100 kg)
DESCRIPTION PART NO.
Mass Set Refer to Table 7 Reusable Molded Transit Case with Foam Inserts
80 kg set 100 kg set
Dust Covers 102846 and 102847 Calibration Report 550100
122577
1 ea. 1 ea. 1 ea. 1 ea.
122577
1 ea. 1 ea.
123057
1 ea. 1 ea. 1 ea. 2 ea.
123035
2 ea. 3 ea.
Page 19 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Table 7. Mass Set Definitions
DESIGNATION PART #
MS-7001-35 401425 35 - 5 2 1 1 2 1 1 1 (4.5) MS-7002-35 401426 35 - 5 2 1 1 2 1 1 1 (4) MS-7002-40 401522 40 - 6 2 1 1 2 1 1 1 (4) MS-7002-45 401496 45 - 7 2 1 1 2 1 1 1 (4) MS-7002-55 401427 55 - 9 2 1 1 2 1 1 1 (4) MS-7002-80 401518 80 6 1 2 1 1 2 1 1 1 (9)
MS-7002-100 401519 100 8 1 2 1 1 2 1 1 1 (9)
TOTAL
MASS (KG)
10
KG 5 KG 2 KG 1 KG
NOMINAL
MASS SET COMPOSITION
0.5
0.2
0.1
KG
KG
KG
TRIM SET
50 TO 0.1 G
Table 8. Mass Set Compatibility
DESIGNATOR
MS-7001-35 35 MS-7002-35 35 MS-7002-40 40 MS-7002-45 45 MS-7002-55 55 MS-7002-80 80 •1
MS-7002-100 100 •1
1
: These mass sets, on certain piston-cylinder sizes, can cause the maximum working pressure of the PG Platform to be
exceeded. Do not exceed the following maximum working pressures:
PG7201: 11 MPa (1 600 psi)
PG7202: When using PC-7200 piston-cylinder modules: 110 MPa (16 000 psi)
When using PC-7300 piston-cylinder modules: 200 MPa (30 000 psi)
PG7302: 500 MPa (72 500 psi)
NOMINAL
TOTAL MASS (KG)
PG7102 PG7202 PG7302 PG7601
1
1
MAKE-UP
MASS (KG)
The mass loading bell and piston make up part of the total mass load but are not
included with the mass set. Piston-cylinder modules are purchased and delivered separately. The mass loading bell is delivered with the PG7000 Platform.
© 1998-2002 DH Instruments, Inc. Page 20
2. INSTALLATION
2.1.2.3 PISTON-CYLINDER MODULE(S)
Table 9. PC-7100/7600 Piston-Cylinder Modules Parts List
Piston-Cylinder Kit 401561 401562 401563 401564
Piston-Cylinder Module 400580 401418 401332 401021 Hermetic PVC Bullet
Case Accessory Kit 401243 401243 401242 401242
O-rings
Insertion Tool 122186 122186 N/A N/A
Calibration Report 550100 550100 550100 550100
10 kPa
PC-7100/7600-10
401642 401642 401642 401642
101918 102380
10 kPa
PC-7100/7600-10 TC
101918 102380
50 kPa
PC-7100/7600-50
101921 102380
200 kPa
PC-7100/7600-200
101921 102380
Table 10. PC-7200 Piston-Cylinder Modules Parts List
Piston-Cylinder Kit 401738 401739 401740 401741 401742 Piston-Cylinder
Module Hermetic PVC
Bullet Case Accessory Kit 401743 401743 401723 401723 401723
O-rings
Anti-Extrusion Ring N/A N/A 123444 123444 123444 Syringe 103046 103046 103046 103046 103046 Syringe tips (3) 103046 (3) 103046 (3) 103046 (3) 103046 (3) 103046 Synturion 6 fluid 401794 401794 - - ­ Sebacate fluid - - 401793 401793 401793 Calibration Report 550100 550100 550100 550100 550100
100 kPa
PC-7200-100
401728 401729 401730 401731 401732
401733 401733 401733 401733 401733
(2) 101295
101102 102109
200 kPa
PC-7200-200
(2) 101295
101102 102109
500 kPa
PC-7200-500
(2) 101295
101102 102109
1 MPa
PC-7200-1
(2) 101295
101102 102109
2 MPa
PC-7300-2
(2) 101295
101102 102109
Table 11. PC-7300 Piston-Cylinder Modules Parts List
100 kPa
PC-7300-100
Piston-Cylinder Kit 401552 401553 401554 401555 401556 401557 Piston-Cylinder
Module Hermetic PVC
Bullet Case Accessory Kit 401545 401545 401545 401544 401544 401544
O-rings
Calibration Reports
401413 401414 401415 401559 401416 401417
401643 401643 401643 401643 401643 401643
101099 101100
550100 550100 550100 550100 550100 550100
Page 21 © 1998-2002 DH Instruments, Inc.
200 kPa
PC-7300-200
101099 101100
500 kPa
PC-7300-500
101099 101100
1 MPa
PC-7300-1
101096 101294
2 MPa
PC-7300-2
101096 101294
5 MPa
PC-7300-5
101096 101294
PG7000™ OPERATION AND MAINTENANCE MANUAL
2.2 SITE REQUIREMENTS
The exact PG7000 system installation is affected by the elements other than the PG7000 Platform that make up the PG7000 system.
When selecting and preparing a site to set up the PG7000 system, the following should be considered:
Ambient Conditions: To achieve optimum metrological performance, ambient conditions should be controlled and maintained within the following:
Temperature: 19 to 23 °C, minimize rate of change of temperature. Relative Humidity: 10 to 60 %RH (non-condensing). Ambient Pressure: Minimize external influences that will cause barometric instability. Air Currents: Do not install the PG7000 Platform under a source of vertical air currents such as an
overhead air conditioning duct. These can blow on the mass load and add unquantified forces.
Vibration: Minimize local vibration. Excessive vibration will reduce the stability of the pressures
defined by PG7000 (vibration affects the floating piston). Excessive high frequency vibration, for example from a vacuum pump on the same table as the PG7000, may affect piston sensitivity.
Bench Stability: Up to 100 kg may be loaded and unloaded onto the PG7000 Platform. The bench on which the PG7000 sits should not deflect significantly under the mass load changes. This can be verified by setting the PG7000 Platform on the bench, leveling it, loading and unloading the complete mass set while observing whether the level setting changes.
Location of Other Components: Plan the space required and a convenient layout for the complete PG7000 system including the PG Terminal, mass set, pressure generation/control component(s), test instrument connection and computer (if present). If using a DHI PPC, MPC, GPC or OPG to generate/control pressure, see its Operation and Maintenance Manual for information on installing it. If a DHI interconnections kit is being used to interconnect the components, see its instruction sheet.
Electrical and Pressure Supplies: Plan the supply of electrical power to the PG Terminal and to the pressure generation/control component(s), if needed. If using a DHI PPC, MPC, GPC or OPG to generate/control pressure, see its Operation and Maintenance Manual for information on the pressures source(s) it needs and how to connect them. Gas supplied to a PC-7100/7600 piston-cylinder module must be clean and dry (instrument grade minimum, high purity preferred) to avoid contaminating the piston-cylinder gap.
Reference Vacuum Supply (PG7601 only): Plan for the vacuum connection to the platform and the location of the reference vacuum pump.
Bell Jar Placement (PG7601 only): Plan a location for the bell jar when it is removed from the platform to load and unload masses. A small shelf is often used for this purpose.
© 1998-2002 DH Instruments, Inc. Page 22
2. INSTALLATION
2.3 SETUP
2.3.1 PREPARING FOR OPERATION
Before setting up the PG7000 system, see Section 2.2 for information on site requirements.
To prepare PG7000 for check out and operation:
Set up the PG7000 Platform (see Section 2.3.1.1). Make the system pressure interconnections (see Section 2.3.1.2). Set up the mass set (see Section 2.3.1.3).
2.3.1.1 SETTING UP THE PLATFORM
To set up the PG7000 Platform proceed as follows: Place the PG7000 Platform on the site table in the desired orientation.
Though the rear panel is usually in the back, any orientation can be used.
Place the PG7000 Terminal at the desired location. Connect the PG7000 Terminal to the PG7000 Platform using the 25-pin
cable supplied.
Connect electrical power (85 to 264 VAC, 50/60 Hz) to the PG7000
Terminal using the power cable supplied. Any grounded power cable with a standard IEC320-313 connection may be used.
(PG7601 Only) - Install the vacuum vent valve kit on the vacuum vent port
on the rear of the PG7000 Platform. Refer to the instruction sheet provided with the vent valve assembly.
(PG7601 Only) - Connect the reference vacuum source and shutoff valve
to the reference vacuum port. Take measures to assure that vacuum oil cannot return to the PG7601.
If an external barometer is being used, establish communications between
the barometer and the PG7000 Platform by connecting the external barometer RS232 port to the PG7000 Platform Com2 port and setting up PG7000 to read and use an external barometer (see Section 3.11.5.4). Set the external barometer head height (see Section 3.11.3.3).
If an automated pressure generation/control component is being used,
establish communications between the automated pressure generation/control component and the PG7000 Platform by connecting the generation/control component RS232 port to the PG7000 Platform COM3 port and setting up PG7000 to use an automated pressure generation/control component (see Section 3.9.9).
Level the platform using the PG7000 Platform’s two front leveling feet and
Page 23 © 1998-2002 DH Instruments, Inc.
the level mounted on the front of the platform.
PG7000™ OPERATION AND MAINTENANCE MANUAL
2.3.1.2 SYSTEM PRESSURE INTERCONNECTIONS
Interconnect the PG7000 Platform, pressure generation/control components and a test connection.
The pressure connection on the PG7000 TEST port is:
PG7102/PG7601: DH200 (DH200 is equivalent to AE SF250C,HIP LF4, etc.). Adapters to convert the DH200 connection to 1/4 in. NPT female are provided with PG7102 and PG7601 Platform accessories.
PG7202: DH500 (DH500 is equivalent to AE F250C, HIP HF4, etc.). Connect the gas test medium pressure control/generation component to the TEST port. If the PG7202 is to be operated in oil, connect the oil pressure control/generation component to the DRAIN port (the gas or oil component is disconnected when not in use, see Section 2.3.3).
PG7302: DH500 (DH500 is equivalent to AE F250C, HIP HF4, etc.).
If using a standard interconnections kit such as PK-7600-PPC/MPC P/N 400985,
PK-7600-PPC/MPC-DIF P/N 401581 or PK-7100-MPCD-DIF P/N 401645, see the instruction sheet provided with the kit for installation instructions. If an OPG1 or GPC1 generator/controller is being used, pressure interconnecting hardware is included with it. See its Operation and Maintenance for connection instructions.
2.3.1.3 SETTING UP THE MASS SET
To install the PG7000 mass set, place the mass loading tray (provided with the mass set accessories) at the desired location then install the individual masses on the mass loading tray.
It is VERY IMPORTANT that the individual masses be installed on the mass
loading tray in proper sequence. This will ensure that PG7000 mass loading instructions are executed properly (carefully follow the instructions provided in Section 2.3.1.3, Installing Masses on the Mass Loading Tray
Installing Masses on the Mass Loading Tray
PG7000 masses are shipped in reusable, molded shipping and storage cases. One of the cases contains a 4.0, 4.5 or 5 kg mass and the masses of 2 kg and under, the other case(s) contain(s) the main masses of 10 or 5 kg each. Each mass is packed in a sealed plastic bag and then placed in a protective shipping insert.
The stability over time of PG7000 pressure measurements is a function of
the stability of the masses loaded on the piston. Precautions should be taken in handling the masses to minimize influences that may change their mass. This includes always wearing protective gloves when handling the masses to avoid contaminating them with body oils and perspiration. Protective gloves are provided in the accessory kits of PG7000 Platforms.
).
© 1998-2002 DH Instruments, Inc. Page 24
2. INSTALLATION
To install the masses on the mass loading tray, proceed as follows:
Open the shipping cases. Install the main masses: The main masses (a series of 10 kg masses if the
mass set is > 55 kg, a series of 5 kg masses if the mass set is < 60 kg) are installed horizontally aligned on the mass loading spindle.
The main masses are sequentially numbered starting with he number 1.
The main mass with the highest sequential number is installed first at the bottom of the stack (i.e., the first mass loaded on the tray). The rest of the
main masses should be stacked upwards in descending order ending with main mass sequential number 1. Be careful NOT to confuse the makeup mass (refer to next item) with main mass 1.
Install the make up mass: The make up mass is a single mass
sequentially numbered 1. It has the same diameter as the main masses. It is a 9 kg mass if the main masses are 10 kg. It is 4 or 4.5 kg if the main masses are 5 kg.
The make up mass is placed on top of the main mass stack. It is always the
top of the stack.
Install the fractionary masses: The fractionary masses are all the masses
of lower value than the main masses and makeup mass. These are masses of 5 kg and under for mass sets with 10 kg main masses. They are masses of 2 kg and under for mass sets with 5 kg main masses. Fractionary masses of 1 to 5 kg are discs with a central hole. Fractionary masses of 100 to 500 g are solid, small diameter pucks. Fractionary masses of 50 g and under are grams masses packed and stored in their own separate storage case.
Fractionary mass discs and pucks are installed vertically in the corresponding slots
in the mass loading tray. Use a consistent setup for the sequence number when there are two masses (e.g., always load sequential number 1 in the front).
2.3.2 INSTALLING A PISTON-CYLINDER MODULE INTO THE PLATFORM
To operate the PG7000 Platform, a piston-cylinder module must be installed in its mounting post. To install a piston-cylinder module in the PG7000 Platform, proceed as follows:
Remove the PG7000 Platform mounting post plug. Unscrew the ORANGE plastic
mounting post plug that is installed in the PG7000 Platform mounting post. Rotate counterclockwise to remove.
Remove the piston-cylinder module from its bullet case. Select a piston-cylinder
module. Open the piston-cylinder module bullet case by rotating its lid counterclockwise. Remove the piston-cylinder module from the bullet case base by unthreading it from the case. Hold the piston-cylinder module body by the knurled area and rotate it counterclockwise.
PC-7200 gas operated, liquid lubricated piston-cylinder modules are delivered with
their lubricating liquid reservoir drained. The reservoir must be filled prior to using the piston-cylinder module. If installing a PC-7200 gas operated, liquid lubricated piston-cylinder module, see Section 5.3.3 for instructions on how to fill the module’s liquid lubrication reservoir prior to installation, then continue the procedure from this point.
When reinstalling an oil or liquid lubricated gas piston-cylinder module in its bullet case, be sure
to empty out any liquid that may have collected in the hole in the bottom of the case. The liquid will not compress, making it difficult to fully close the case and could result in damaging it.
Page 25 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Place the piston-cylinder module in the PG7000 Platform mounting post. Place
the piston-cylinder module (thread down) into the PG7000 Platform mounting post (see Figure 4 below).
If installing the piston-cylinder module into a PG7302 or a PG7202 to be operated
with oil, first use the oil generation control component to fill the counterbore in the mounting post with oil until it just starts to overflow.
Purge the air from under the piston-cylinder module (PC-7300 modules only in
PG7302 or PG7202). Rotate the piston-cylinder module clockwise until all threads are
engaged and there is no gap between the piston-cylinder module and the mounting post. Back the piston-cylinder module off slightly by rotating it counterclockwise 3/4 turn. Slowly supply additional oil to the mounting post from the pressure generation/control component. Watch the oil run off tube on the bottom right of the platform. As soon as oil appears or can be seen flowing, stop the oil supply to the TEST port.
Screw the piston-cylinder module into the PG7000 Platform mounting post. Rotate
the piston-cylinder module clockwise until all threads are engaged and there is NO gap between the piston-cylinder module and the PG7000 mounting post. Slight resistance will be encountered in the second half of travel as the piston-cylinder module O-rings seat in the mounting post.
Low torque manual rotation is all that should be required to fully seat the piston-cylinder
module into the PG7000 mounting post. Never force the piston-cylinder module into the mounting post.
Always maintain PG7202 and PG7302 piston- cylinder modules vertical with the
piston cap up. Do not invert the assembly as this might allow liquid to run up into the piston head and into the adjustment mass and cap. Liquid contamination of the piston head and cap changes the mass of the piston assembly and could lead to out of tolerance pressure definitions at low mass loads. If liquid contaminates the adjustment mass and cap, disassemble the module and clean it (see Sections 5.3.1,
5.3.4, 5.3.2.2).
© 1998-2002 DH Instruments, Inc. Page 26
Figure 4. Piston-Cylinder Module Installation
2. INSTALLATION
2.3.3 SWITCHING A PG7202 BETWEEN GAS OPERATION AND OIL OPERATION
PG7202 can be operated with gas as the pressurized medium using PC-7200 gas operated, liquid lubricated modules or with oil as the pressurized medium using oil operated PC-7300 modules.
PC-7200 gas operated, liquid lubricated piston-cylinder modules can be operated in gas
oil filled with oil and operated in oil. Oil operation of PC-7202 modules is not recommended for routine operation. It can be useful in very specific crossfloating circumstances, particularly when establishing a calibration link between independent gas operated and oil operated piston gauges. When switching PC-7200 module between oil and gas and oil operation, see Section 5.3.3 for information on emptying excess oil from the module.
Switching a PG7202 from gas to oil operation
Only the high pressure PC-7300 oil modules may be used in the PG7202 platform
(PC-7300-1, -2, -5)
Disconnect the gas generation/control system from the TEST port. Disconnect the
tube at the DH500 TEST port connection on the back of the PG7202. Loosely install a DH500 plug in the TEST port.
Connect the oil generation/control system to the DRAIN port. Connect a tube from
the oil generation/control system to the PG7202 DRAIN port and tighten it (torque DH500 glands to 15 Nm (12 ft.lb)).
Fill the PG7202 mounting post with oil. Hand tighten the DH500 plug in the TEST
port. Use the oil generation/control component to fill the PG7202 mounting post with oil. Fill to the edge of the second step in the mounting post. Place a paper towel under the TEST port plug and loosen the DH500 plug allowing oil to run out until it is at the level of the first step in the mounting post and there is no air in the run off oil. If there is still air in the run off, repeat the operation. After filling the mounting post, tighten the DH500 plug (torque DH500 glands to 15 Nm (12 ft.lb)).
Install a PC-7300 oil operated piston-cylinder module in the PG7202 platform.
Install the module and purge the air from underneath it (see Section2.3.2).
Operate with oil as the test medium. The PG7202 can now be operated with oil as the
test medium.
The maximum working pressure of the PG7202 platform when used in oil with a
PC-7300 module is 200 MPa (30 000 psi). The maximum pressure when using a PC-7200 module is 110 MPa (16 000 psi). Do not exceed this limit.
Page 27 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Switching a PG7202 from oil to gas operation
Remove the piston-cylinder module. Disinstall the PC-7300 oil operated piston-cylinder
module for the PG7202 platform.
Disconnect the oil generation/control system from the DRAIN port. Place a paper
towel under the DRAIN port and disconnect the tube to the oil generation/control system. Let all the oil run out of the PG7202 platform.
Remove the DH500 plug from the TEST port. Place a paper towel under the TEST
port and remove the DH500 plug. Let all the oil run out of the PG7202 platform..
Install a PC-7200 gas operated, liquid lubricated piston-cylinder module in the
PG7202 platform. Install the piston-cylinder module (see Section 2.3.2).
Connect the gas generation/control system to the TEST port. Connect a tube from
the oil generation/control system to the PG7202 TEST port and tighten it (torque DH500 glands to 15 Nm (12 ft.lb)).
Prepurge the oil from the PG7202 mounting post. Hold a paper towel lightly over the
DRAIN port opening. Leaving the drain port open, use the gas generation/control component to flow enough gas through the mounting post to just lift the piston.
Purge the PG7202 mounting post. Purge the PG7202 mouting post using the standard
purging procedure (see Section 5.2.4) and finish by tightening the plug in the DRAIN port.
Operate with gas as the test medium. The PG7202 can now be operated with gas as
the test medium.
The maximum working pressure of the PG7202 platform when used with a PC-7200
module is 110 MPa (16 000 psi). Do not exceed this limit.
2.4 POWER UP AND VERIFICATION
2.4.1 POWER UP
Turn the PG7000 power ON by pressing the power ON/OFF switch on the rear panel of the PG Terminal. Observe the PG terminal display as the terminal connects with the PG7000 Platform, tests, initializes and goes to the main run screen (see Section 3.7).
If <….Searching…..> displays for more than 5 seconds, the communications between the PG7000 and the PG Terminal are failing. Check that the PG7000 to PG Terminal cable is properly installed.
If PG7000 fails to reach the main run screen, service may be required. Record the sequence of operations and displays observed and contact a DHI Authorized Service Provider (see Table 30).
2.4.2 CHECK THAT ON-BOARD PISTON-CYLINDER MODULE AND MASS SET INFORMATION ARE CORRECT
PG7000 uses stored piston-cylinder and mass set metrological information to calculate the reference pressures it defines (see Section 3.1). For the pressure values to be correct, the stored metrological information on the piston-cylinder, mass set and mass loading bell must be correct. Before using PG7000 for accurate pressure definition, the validity of the stored information should be verified. This consists of comparing the piston-cylinder, mass set and mass loading bell information stored in PG7000 to the information in the current piston-cylinder and mass set calibration reports.
To verify the PG7000 piston-cylinder, mass set and mass loading bell information, use the piston-cylinder and mass set viewing capabilities accessed by pressing [SPECIAL],
© 1998-2002 DH Instruments, Inc. Page 28
2. INSTALLATION
<1PC/MS> (see Section 3.11.1). Compare all the information contained in the PG7000
piston-cylinder, mass set and mass loading bell files to the information on the current piston-cylinder, mass set and mass loading bell calibration reports.
2.4.3 SET LOCAL GRAVITY VALUE
PG7000 uses the value of local acceleration due to gravity (gl) in its calculation of the reference pressure it defines (see Section 3.1). The correct value of local acceleration due to gravity at the site of PG7000 use must be entered. This is accomplished by pressing [SPECIAL], <6gl> (see Section 3.11.6) and editing the value of local gravity.
2.4.4 SETUP PRESSURE EQUATION VARIABLE INPUT SOURCES
PG7000 uses many variables in calculating defined pressures. The sources of the variables are determined by the current SETUP file. SETUP files are viewed, created, edited and selected using the SETUP function accessed by pressing [SETUP] (see Section 3.10). A factory SETUP file is available and already selected on a new PG7000, but the operator may desire to customize it. The factory setup file assumes that PG7000’s internal measurement values will be used whenever possible.
2.4.5 CHECK PROPER OPERATION OF AMBIENT CONDITION MEASUREMENTS
PG7000 automatically measures ambient conditions and uses these conditions in its pressure calculations.
To verify that the ambient condition measurements are operating properly proceed as follows:
Display current ambient condition readings: Press [AMBIENT]. The ambient
conditions run screen is displayed (see Section 3.9.6).
Verify proper ambient condition readings: Compare the ambient condition values
displayed to the actual values of ambient conditions. Refer to the ambient condition measurement specifications when evaluating the ambient readings (see Section 1.2.1.2).
The unit of measure in which ambient pressure is displayed is the same as the unit
selected by pressing [UNIT] (see Section 3.9.3). Units of measure in which other ambient condition values are expressed cannot be changed.
PG7000 allows the source of ambient condition values used in reference pressure
calculations to be specified. The source may be PG7000’s on-board measurements, default values or operator entered values. See Section 3.10 for information on specifying the source of ambient condition values used by PG7000 in reference pressure calculations.
Page 29 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
2.4.6 APPLY PRESSURE TO THE PISTON-CYLINDER MODULE
This section assumes that the PG7000 system has already been set up, including
pressure interconnection (see Section 2.3).
Before applying pressure to the PG7000 system, be sure that all pressure vessels and
connections are rated for the pressure levels that will be applied and that all connections have been properly tightened.
Continuing with the PG7000 set up and check out requires applying pressure to the piston­cylinder module and floating the piston.
Proceed as follows:
Turn OFF automated piston rotation (if present) and automated pressure
generation (if present). This will prevent the automated rotation and pressure
generation features (if present) from interfering during verification of these features (see Sections 3.9.8 and 3.9.9 for information on automated piston rotation and pressure generation).
Press [ROTATE] until <Turning OFF automatic rotation> displays momentarily. If
PG7000 does NOT have the motorized rotation option, <Automatic rotation not available> displays momentarily.
Press [GEN] until <Turning OFF automated generation> displays momentarily. Load mass on the piston. Install the mass loading bell on the piston. Then load the
make up mass (9, 4.5 or 4 kg depending on the mass set) (see Section 2.3.1.3).
Float the piston. Use the pressure generation/control component of the PG7000
system to apply pressure under the piston through the PG7000 Platform TEST port. The piston will float at a pressure approximately equal to the piston mass to pressure conversion factor multiplied by the mass load in kg. The piston-cylinder conversion factor is marked on the top of the piston cap and is in either kPa or MPa per kilogram [kPa/kg or MPa/kg].
If the piston cannot be floated because it immediately sinks down from a float position,
there is a leak in the pressure system. Identify and eliminate leaks until the piston, once floated, falls at a rate equal to or less than the nominal fall rate given in the specifications of the piston-cylinder module being used (see Section 1.2.2).
2.4.7 CHECK PROPER BEHAVIOR OF MOTORIZED PISTON ROTATION (IF PRESENT)
Motorized piston rotation is a standard feature on PG7601 and an optional feature on PG7102, PG7202 and PG7302.
The motorized rotation feature can be set to engage and disengage automatically as needed at the appropriate times to maintain the floating piston rotating within a set rotation rate range
(see Section 3.9.8). Motorized rotation can also be activated manually by pressing [ Section 3.9.13).
Turn automated rotation OFF by pressing [ROTATE]. Load at least the mass bell on the piston, float the piston and press [
cause the mass bell and piston to begin rotating. Within 5 to 30 seconds, depending on the mass load, the rotation rate should reach 80 rpm for PG7601 or about 50 rpm for PG7102 or PG7302. Current rotation rate can be observed by pressing [SYSTEM] (see Section 3.9.5).
© 1998-2002 DH Instruments, Inc. Page 30
] (see
]. The motorized rotation system should engage and
2. INSTALLATION
2.4.8 CHECK PROPER OPERATION OF PISTON BEHAVIOR MEASUREMENTS
Float the piston and rotate it (see Sections 2.4.6 and 2.4.7). Press [SYSTEM] once to reach the first SYSTEM run screen. Verify that the piston position,
piston fall/rise rate, piston rotation rate and piston rotation decay rate are indicating correctly (see Section 3.9.5). The piston position reading system may be adjusted using an on-board procedure if necessary (see Section 5.2.2).
Press [SYSTEM] again to reach the second SYSTEM run screen. Verify that the piston-cylinder temperature and temperature rate of change are indicating correctly (see Section 3.9.5). If checking a PG7601 Platform, verify that the vacuum reference measurement is operating correctly (see Section 2.4.8.1).
2.4.8.1 VERIFY VACUUM REFERENCE (PG7601 ONLY)
PG7601 includes provisions for establishing and measuring a vacuum reference. To verify the vacuum reference capability:
Install a piston-cylinder module (see Section 2.3.2). Install the bell jar on the PG7601 Platform (the bell jar aligns on the PG7601
vacuum plate and seals itself).
Apply a vacuum through the reference vacuum port (KF25 port on front left
side of platform).
Press [AMBIENT] twice to observe the value of vacuum read by the
PG7601’s built-in vacuum gauge.
If a vacuum pump of adequate capacity has been correctly connected to the reference vacuum port, the vacuum read by the PG7601 built-in vacuum gauge should go to 4 Pascal [Pa] or lower in less than five minutes on the first pump down and two to three minutes on immediately subsequent pump downs.
If this performance is NOT achieved:
The vacuum pump may be inadequate.
The connection of the vacuum pump to the PG7601 platform may have leaks
or excessive restrictions.
The PG7601 built-in vacuum gauge may be incorrect.
There may be a leak in the PG7601.
Page 31 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
2.4.9 CHECK AUTOMATED PRESSURE GENERATION (IF PRESENT)
Before applying pressure to the PG7000 system, be sure that all pressure vessels and
connections are rated for the pressure levels that will be applied and that all connections have been properly tightened.
To check automated pressure generation/control: Verify that the automated pressure generation/control component is properly connected
to the system (see Section 2.3.1.2).
Press [P
OR M], <1pressure> to select pressure entry mode (see Section 3.9.12). Press
[ENTER] and enter a pressure value to be generated and follow the mass loading
instruction (see Section 3.6).
When operation has returned to the main run screen, turn ON automated pressure
generation control, if available, by pressing [GEN] (see Section 3.9.9).
Verify the pressure generation/control component properly generates pressure and floats
the PG7000 piston within the measuring zone.
2.4.10 CHECK/SET SECURITY LEVEL
PG7000 has a security system based on User Levels. By default, the security system is set to low and NO password is required to change the security level. See Section 3.11.8 for information on the security system. As part of the PG7000 startup, set your desired security level and a password.
PG7000 is delivered with the security level set to low to avoid inadvertent altering of
critical internal settings but with access to changing security levels unrestricted. It is recommended that the low security level be maintained at all times and password protection be implemented if control over setting of security levels is desired.
2.4.11 ADDITIONAL PRECAUTIONS TO TAKE BEFORE MAKING PRESSURE MEASUREMENTS
Before using PG7000 to make accurate pressure measurements, consider the following:
Select/activate the correct piston-cylinder module, mass set and mass loading bell
(see Sections 3.9.2, 3.11.1.10, 3.11.1.15).
Enter the correct value of local gravity at the site of use (see Section 3.11.6).
Consider head corrections (see Sections 3.9.7 and 3.11.3).
Level the PG7000 Platform properly (see Section 2.3.1.1).
Select the correct pressure unit of measure and measurement mode (see Sections 3.9.3
and 3.9.5).
Verify that the settings for the sources of variables to be used by PG7000 in its
calculations of reference pressures are those desired (see Section 3.10).
Verify that the piston-cylinder module is correctly cleaned and operating properly
(see Section 5.3).
PG7202 only: Ensure that the piston-cylinder module liquid reservoir is filled (see Section 5.3.3).
Verify that there are NO leaks in the pressure system.
© 1998-2002 DH Instruments, Inc. Page 32
2. INSTALLATION
2.5 SHORT TERM STORAGE
The following is recommended for short term storage of PG7000.
Remove all masses from the PG7000 Platform.  Vent all circuits to atmosphere.  Turn OFF power using the power switch on the rear of the PG7000 Terminal.
Cover the PG7000 Platform and mass set with their dust covers.
Page 33 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
N
N
OOTTEES
S
© 1998-2002 DH Instruments, Inc. Page 34
3. GENERAL OPERATION
33..
G
EENNEERRAALL
G
O
PPEERRAATTIIOON
O
N
3.1 FUNDAMENTAL OPERATING PRINCIPLES
PG7000s operate on the principle of the piston gauge in which pressure is defined by balancing it against a known force on a known area (see Figure 5). The known area is defined by a vertically mounted piston rotating in a cylinder and the known force is applied to the piston by loading it with known mass subjected to acceleration due to gravity. When the force applied by the pressure and the force applied by the mass accelerated by gravity are in equilibrium, the piston floats and the pressure under the piston remains constant. The pressure can be calculated following the equation in Figure 5 (see also, Section 7.2). Generally, the pressurized fluid under the piston also lubricates the gap between the piston and the cylinder. PG7202 uses a unique gas operated, liquid lubricated piston-cylinder (see Section 3.1.1).
Figure 5. Piston Gauge Operating Principle
The PG7000 Platform is designed to mount a variety of piston-cylinder sizes, allow pressure to be applied under the piston and allow masses to be loaded on top of the piston. There are different PG7000 models depending upon whether the pressure medium is oil or gas and whether a vacuum reference is needed.
The measurement uncertainty in the pressure defined by the piston gauge depends on the uncertainty in the effective area of the piston-cylinder and the force applied by the mass accelerated by gravity. PG7000 stores the calibrated values of the piston-cylinders and masses it uses in on-board files (see Section 3.11.1). To determine the effective area of the piston-cylinder and the force applied by the masses under actual operating conditions, a number of influences on these values must be quantified and taken into consideration. For this reason, PG7000 includes extensive features to monitor the behavior and conditions of the piston-cylinder as well as ambient conditions that affect pressure definition (see Sections 3.9.5 and 3.9.6). PG7000 uses the piston-cylinder, mass and ambient condition information to calculate the pressure defined by a given mass load or the mass load needed to define a given pressure (see Section 7.2). The source of each value used by PG7000 in its calculations can be selected by the user between PG7000’s internal measurements, default values or user entered values. These sources are defined in SETUP files (see Section 3.10).
Page 35 ©1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Once PG7000 has been set up, it is used in day-to-day work either to define pressures applied to a device or system under test or to measure a stable pressure. To interface with the PG terminal, the operator:
Selects the appropriate piston-cylinder to cover the pressure range (see Section 3.11.1.5). Selects the desired pressure unit of measure (see Section 3.9.3). Selects the desired pressure measurement mode (gauge, absolute, differential) (see Section 3.9.4). Sets the head difference between the PG7000 and the device under test (see Section 3.9.7). Selects mass to pressure or pressure to mass operating mode (see Section 3.9.12). Enters a pressure to define or a current mass load to calculate (see Section 3.9.11.1 and 3.9.11.2). Loads masses, floats piston and defines pressure.
3.1.1 GAS OPERATED, LIQUID LUBRICATED PISTON-CYLINDER OPERATING PRINCIPLE (PG7202)
PG7202 provides very high pressure gas pressure operation using a unique gas operated, liquid lubricated piston-cylinder system.
The principle of operation of the gas operated, liquid lubricated piston-cylinder is simple but very effective (see Figure 6). The measured gas pressure, Pg, is applied to the bottom of the piston and to the top of a liquid reservoir located around the cylinder. The reservoir is connected to the gap between the piston and the cylinder through lateral holes near the bottom of the cylinder, allowing liquid from the reservoir to enter the gap. The pressure of the liquid in the gap, Pl, is equal to the gas pressure Pg, plus the liquid head, h. Therefore, the liquid pressure in the gap is always higher than the gas pressure by the amount of the liquid head regardless of the gas pressure value. Since h is small and the space between the piston and cylinder is typically < 1 micron, the bleed of liquid from the bottom of the cylinder towa rds the gas pressure is extremely small. The mounting post of the 7202 piston gauge is configured so this minute amount of liquid drops directly into a sump that is deadened (see Section 5.2.4, 3.1.1) and not in the flow path of test gas into and out of the system. Though molecules of the liquid may migrate through the gas, no significant contamination of the test system occurs. Because the liquid reservoir is contained in the piston-cylinder module, piston-cylinders can be removed and installed in the PG7202 piston gauge platform with no loss of liquid from the reservoir. All PC-7200 piston-cylinder modules can be delivered using Krytox, a fluorinated synthetic fluid, to lubricate the piston-cylinder in applications where the system must remain perfectly free of hydrocarbons (e.g. when calibrating instrumentation for oxygen service).
PC-7200 gas operated, liquid lubricated piston-cylinder modules are delivered with
their lubricating liquid reservoir drained. The reservoir must be filled prior to using the piston-cylinder module and then regularly when used (see Section 5.3.3)
© 1998-2002 DH Instruments, Inc. Page 36
3. GENERAL OPERATION
Figure 6. Gas Operated, Liquid Lubricated
Piston-Cylinder (PC-7200) Operating Principle
3.2 KEYPAD LAYOUT AND PROTOCOL
PG7000 has a 4 x 4 keypad for local operator access to direct functions, function menus and for data entry.
1. The Function/Data keys allow very commonly used functions to be accessed directly from the main run screen by a single keystroke. The name of the function is on the bottom half of the key (see Section
3.9.1). These keys enter numerical values when editing.
2. The Editing and Execution keys are for execution, suspending execution, backing up in menus and editing entries.
3. The Menu/Data keys provide access to function menus from the main run screen. The menu name is on the bottom half of the key. The SETUP menu is for more frequently used functions. The SPECIAL menu is for functions that are NOT generally used as a part of day to day operation. These keys enter numerical values when editing.
Figure 7. PG7000 Keypad Layout
Key press confirmation is provided by both tactile and audible feedback. A single beep confirms a valid entry. A descending two note tone signals an invalid entry. The audible valid entry feedback can be suppressed or modified by pressing [SPECIAL] and selecting <5prefs>, <2sound> (see Section
3.11.4.2). Pressing the [ENTER] key generally causes execution or forward movement in the menu tree.
Page 37 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
2
Pressing the [ESCAPE] key generally allows movement back in the menu tree and/or causes execution to cease or suspend without changes being implemented. Pressing [ESCAPE] repeatedly eventually returns to the main run screen. From the main run screen, pressing [ESCAPE] allows momentary viewing of the PG7000 identification screen.
Pressing the [+/-] key changes a numerical sign when editing. It also toggles through multiple screens when available.
Pressing the [] and [] keys when editing allows reverse and forward cursor movement when editing data entry. These keys are also used to scroll through choices.
Menu selections can be made by pressing the number of the selection directly or by pressing [] and [] to place the cursor on the number of the desired selection and pressing [ENTER].
Some screens go beyond the two lines provided by the display. This is indicated by a flashing arrow in
the second line of the display. Press [] and [] to move the cursor to access the lines that are NOT visible or directly enter the number of the hidden menu choice if you know it.
3.3 SOUNDS
The PG Terminal is equipped with a variable frequency tone device to provide audible feedback and alarms. Some sounds can be modified and all sounds can be suppressed (see Section 3.11.4.2). Sounds are used for the following indications:
Valid key press
Invalid key press
Piston left end of stroke high
or low
Brief high frequency beep. Three rapid, low frequency beeps. Three rapid valid key press beeps. Piston was at low stop or high stop and
just entered spring zone (see Section 3.5).
3.4 PRESSURE READY/NOT READY INDICATION
The three characters on the top line, far left, of the main run screen provide a pressure Ready/Not Ready indication. This indication is intended to give the user a clear and objective indication of when PG7000 conditions are such that the value of pressure it is defining is valid and in tolerance. There are three Ready/Not Ready indication characters to indicate the status of the three main Ready/Not Ready criteria. The Ready/Not Ready indication characters are shown on the first line, top left hand side, of the main run screen.
1. Piston position and vertical movement.
2. Piston rotation.
3. Reference vacuum (PG7601 in absolute by vacuum measurement mode only).
*** 100.4755 kPa g h
+ 0.1 mm 10.00564 kg
For each Ready/Not Ready indication character, <*> indicates a Ready condition. Therefore, <***> or <** > indicates that all conditions necessary for an in tolerance pressure definition are present. Any indication other than <*> indicates Not Ready.
3
See Sections 3.4.1, 3.4.2 and 3.4.3 for details on each of the three Ready/Not Ready indicating characters.
The criteria used to distinguish between Ready and Not Ready conditions can be customized by the
user (see Sections 3.4.1, 3.4.2, 3.4.3).
© 1998-2002 DH Instruments, Inc. Page 38
3. GENERAL OPERATION
3.4.1 PISTON POSITION READY/NOT READY
The piston position Ready/Not Ready character indicates Ready or Not Ready based on the position of the piston in its vertical stroke (see Section 3.5) and an automated measure generation status (see Section 3.9.9). This ensures that pressure definitions will be made with the piston not more than a certain distance from mid-float position and that measurements will not be made while pressure is being adjusted.
The piston position Ready/Not Ready character is the first character from the left on the top line of the main run screen.
The piston position Ready/Not Ready criterion is determined by the current SETUP file and can be customized by the user (see Section 3.10).
Piston position Ready/Not Ready character indications include: <*> Piston position Ready (within the position limits specified in the current SETUP file)
(see Section 3.5).
<> Piston position Not Ready, low (below the position limits specified in the current
SETUP file, see Section 3.10). The <> flashes if the piston is not at the bottom stop position to alert the user that this indicator is Not Ready.
<> Piston position Not Ready, high (above the position limits specified in the current
SETUP file) (see Section 3.10). The <> flashes if the piston is not at the top stop position to alert the user that this indicator is Not Ready.
<?> Piston position not known (current specified mass load is less than the load of the
piston + bell). The bell must be installed for PG7000 piston position measurement to operate correctly so piston position values shown are not valid when the bell is not installed.
<T> Tare PG7000 is Not Ready (PG7102 and PG7202 only). Indicates that piston
position or rotation rate is Not Ready on the tare PG7000 in high line differential mode (see Section 3.9.4.2).
Piston position always indicates Not Ready if automated pressure generation is
adjusting pressure, regardless of actual piston position.
In PG7102 and PG7202 high line differential pressure mode (see Section 3.9.4.2), the
piston position Ready/Not Ready indicator applies to the pistons of both the tare and the reference PG7000. For Ready to be indicated, both pistons must be within the ready limits for piston position.
3.4.2 PISTON ROTATION READY/NOT READY
The piston rotation Ready/Not Ready character indicates Ready or Not Ready based on the rotation rate of the piston. This ensures that pressure definitions will be made within consistent piston rotation rate limits.
The piston rotation Ready/Not Ready character is the second character from the left on the top line of the main run screen.
The piston rotation rate Ready/Not Ready criterion is specific to the currently active piston-cylinder module and can be edited, within limits, by the user (see Sections 3.11.1.1).
Page 39 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Piston rotation rate Ready/Not Ready character indications include: <*> Rotation rate Ready: Rotation rate is within the rotation rate limits specified in the
current piston-cylinder module file) (see Section 3.11.1.1).
<> Rotation rate Not Ready, low: Rotation rate is less than the rotation rate limits
<
specified in the current piston-cylinder module file) (see Section 3.11.1.1) or motorized rotation system is currently engaged. Note that the low rotation limit is automatically reduced when the mass loaded on the piston is less than 3 kg for
PG7202 and PG7302 or 2.5 kg for PG7102 or PG7601. The < is floating to alert the user that this indicator is Not Ready.
>> Rotation rate Not Ready, high: Rotation rate is greater than the rotation rate limits
<
specified in the current piston-cylinder module file (see Section 3.11.1.1). The < flashes if the piston is floating to alert the user that this indicator is Not Ready.
<?> Rotation rate not known: Current specified mass load is less than the load of the
(piston + bell). The bell must be installed for PG7000 piston rotation rate measurement to operate correctly so piston rotation rate cannot be measured when the bell is not installed.
Under 3 kg mass load for PG7202 and PG7302 or 2.5 kg for PG7601 and PG7102, the low
rotation rate Ready limit automatically goes to the minimum Ready limit (2 rpm for PG7202 and PG7302; 5 rpm for PG7102 and PG7601).
<> flashes if the piston
>>
In PG7102 and PG7202 high line differential pressure mode (see Section 3.9.4.2), the
piston rotation rate Ready/Not Ready indicator applies to the pistons of both the tare and the reference PG7000. For Ready to be indicated, both pistons must be within the ready limits for piston rotation rate.
3.4.3 VACUUM REFERENCE READY/NOT READY (PG7601 ONLY)
The vacuum reference Ready/Not Ready character is only used with PG7601, as it is the only PG7000 model with vacuum reference capability. It is only active when operating in absolute by vacuum mode (see Section 3.9.4).
The vacuum reference Ready/Not Ready character indicates Ready or Not Ready based on the value of reference vacuum when making measurements in absolute by vacuum mode. This ensures that definitions of absolute pressure with a vacuum reference will be made with the vacuum under the PG7601 bell jar lower than a specified value. When the vacuum is not low enough, vacuum measurement errors may be excessive.
The vacuum reference Ready/Not Ready character is the third character from the left on the top line of the main run screen.
The vacuum reference Ready/Not Ready criterion is determined by the current SETUP file and can be customized by the user (see Section 3.10). The vacuum reference criterion is a fixed value that can be customized by the user when the vacuum reference selection in the SETUP file is internal. If the selection in the SETUP file is NOT internal, the vacuum reference Ready/Not Ready character always indicates Ready and the value cannot be customized.
Vacuum reference Ready/Not Ready character indications include: < > (Blank) Vacuum reference Ready/Not Ready is not in use. This is not a PG7601;
or if PG7601, current measurement mode is not absolute by vacuum.
<*> Vacuum reference Ready. Vacuum value is below limit specified in the current
SETUP file if source is internal OR source is default or user and the vacuum value is not a measured value (see Section 3.10).
< > > Vacuum reference Not Ready. Current SETUP file source for vacuum is internal
and vacuum value is above the limit specified (see Section 3.10). The <v> flashes if the piston is floating to alert the user that this indicator is Not Ready.
© 1998-2002 DH Instruments, Inc. Page 40
3. GENERAL OPERATION
3.5 PISTON POSITION
When operating a PG7000 piston gauge, reference pressure values are defined by loading known mass values on the piston and adjusting the pressure to float the piston. Piston position is measured and displayed real time on the MAIN run screen (see Section 3.7) and in the first SYSTEM run screen (see Section 3.9.5). Piston position is used as a criterion for the Ready/Not Ready indication as valid measurements can only be made when the piston is in the correct position (see Section 3.4.1).
The full piston stroke is ± 4.5 mm from the midstroke position. The stroke is divided into different positions and zones as illustrated in Figure 7. These zones are:
High and low stops: The piston is at the minimum or maximum end of stroke. The pressure applied to the piston is higher (at high stop) or lower (at low stop) than that corresponding to the mass loaded on the piston. The high and low stop positions are fixed.
High and low spring zones: The combination of pressure and the force of the high or low stop springs have caused the piston to leave the stop. The pressure applied to the piston is within the equivalent of 2 kg of the pressure corresponding to the mass loaded on the piston. The high and low spring zones indicate the piston is about to float. The spring zone positions are fixed.
High and low measurement zones: The piston is within the zone in which a Ready measurement can be made (see Section 3.4.1). The pressure applied to the piston is the pressure corresponding to the mass loaded on the piston. The default value of the high and low measurement zones is ± 2.5 mm around midstroke position. This value can be adjusted in the SETUP file (see Section 2.10).
Midstroke: The piston is at the middle of its stroke. The bottom of the piston (or its equivalent for hollow pistons) is at the reference level marked on the mounting post (see Section 3.9.7). There is equal stroke available to the high and low stops.
The piston position monitoring system is driven by the internal ring in the base of the mass
loading bell. When the bell is not installed, piston position cannot be measured. If the current mass load is less than the mass of the piston + bell, PG7000 will display < ---- > where piston position is normally displayed. If the current mass load is greater than the mass of the piston + bell but the bell is not actually installed, the piston position indication is not valid.
[mm]
HIGH STOP
HIGH READY LIMIT
MIDSTROKE
LOW READY LIMIT
LOW STOP
ADJUSTABLE
(SYMETRICALLY)
+4.0
+3.0 +2.5
-3.0
0.0
-2.5
-4.0
HIGH SPRING ZONE
HIGH SPRI N G ZONE
(NOT READY )
(NOT READY)
HIGH
MEASUREMENT
ZONE
(READY)
LOW
MEASUREMENT
ZONE
(READY)
LOW SPRING ZONE
(NOT READY)
Page 41 © 1998-2002 DH Instruments, Inc.
Figure 8. Piston Stroke and Zones
PG7000™ OPERATION AND MAINTENANCE MANUAL
3.6 MASS LOADING PROTOCOL
PURPOSE
To provide the operator with mass loading instructions and allow mass entry in convenient nominal values which PG7000 can accurately convert to measured mass values to determine the actual mass load.
PRINCIPLE
All PG7000 masses of 0.1 kg and above, including those in the mass set, the mass loading bell and the piston assembly, are adjusted so that their true mass is within ± 20 ppm of their nominal value. The nominal value is marked on each mass. Each mass’s actual individual value is measured more accurately than ± 20 ppm and reported in the mass set, mass loading bell or piston-cylinder module calibration report. These measured actual values are used by PG7000 in all of its defined pressure calculations. The nominal mass values, and the sequential numbers of the nominal masses when there are several of the same value, are used by PG7000 to describe the mass to load or the mass that is loaded. Following a few simple mass loading rules allows PG7000 to accurately transform actual mass values into nominal mass values and vice-versa so that mass loading instructions to the operator and the operator mass entries can be made in simple nominal mass instructions while representing actual individual mass values.
Since the nominal mass values written on the masses and the actual values of the individual masses are different, in pressure to mass mode (see Section 3.9.12) the actual mass value loaded on the piston will be different from the mass loading instruction. In the same manner, in mass to pressure mode the nominal value of the mass load that the operator enters is different from the actual mass loaded on the piston. The mass value shown in the MAIN run screen (see Section 3.7) is always the actual mass value. The mass loading instruction given in pressure to mass mode and the mass value entered by the operator in mass to pressure mode is always the nominal mass value. If PG7000 mass loading protocol is followed, the conversion from nominal mass to actual mass occurs correctly allowing very simple nominal mass loading and accounting for the operator while using very accurate measured mass values for metrological calculations.
OPERATION
PG7000 instructions to the operator of mass to load, and operator entries of the mass that is loaded, are always expressed in terms of nominal mass within 0.1 kg and in terms of grams for values under 0.1 kg.
In pressure to mass mode, the instruction of the mass to load to achieve the requested pressure is formatted:
In mass to pressure mode, the entry of the mass currently loaded on the piston is formatted:
kkk.k and gg.gg must be expressed and loaded following the mass loading rules below:
Load nominal mass: kg and gkkk.k gg.gg
Nominal mass load: kg and gkkk.k gg.gg
Mass Loading Rules
See Sections 2.3.1.3, Installing Masses On The Mass Loading Tray and protocol information. Refer to display examples immediately above to identify kkk.k and gg.gg. See EXAMPLES: Mass Loading below for mass loading examples.
© 1998-2002 DH Instruments, Inc. Page 42
and 3.6. for PG7000 mass set principles
3. GENERAL OPERATION
PG7000 mass loading entries and instructions are always formatted: kkk.k kg and nn.nn g
The mass set being used must be selected as the active mass set (see Section 3.11.1.10) and must be properly set up prior to use (see Section 3.11.1.6).
kkk.k is made up of the piston, the mass loading bell and mass set masses of 0.1 kg and greater.
kkk.k always includes the mass loading bell and then the makeup mass, if possible.
kkk.k is made up of the largest masses possible rather than a combination of smaller masses.
EXAMPLE: To load 5 kg on a PG7601:
USE the piston (0.2 kg) + the mass loading bell (0.3 kg) + the 4.5 kg makeup mass. DO NOT USE the piston + the mass loading bell + 2 kg #1 + 2 kg #2 + 0.5 kg #1.
When several masses of the same nominal value are included in kkk.k, they are loaded in numerical sequence, low to high.
EXAMPLE: When loading three 5 kg masses:
USE 5 kg mass #1, #2 and #3. DO NOT USE 5 kg mass #4, #3, #1.
This rule will be followed automatically if masses are installed and used as described in Section 3.6.
gg.gg is made up of mass from the gram trim mass set (masses of 50 g to 0.01 g). These masses can be loaded in any order.
When PG7000 provides mass loading instructions and calculates the true mass of the mass
currently loaded, it assumes that the mass set in use has been set up correctly (see Section 2.3.1.3). For PG7000 mass loading protocol to operate properly, the mass set in use must be EXACTLY the mass set that has been defined by the add and/or edit mass function (see Section 3.11.1.6).
In PG7102 and PG7202 High Line Differential mode (see Section 3.9.4.2), there are two types of mass
loading instructions: line pressure setting and differential pressure setting. Both follow conventional PG7000 mass loading protocol. The line pressure mass instructions are always given with 0.1 kg resolution. This is to preserve the smaller masses for setting the differential pressure. The differential pressure mass loading instructions follow conventional mass loading protocol using the masses that remain after the line pressure has been set. It may be necessary to adjust the line pressure value to assure that adequate masses remain to set the desired differential pressure. For example, if the line pressure requires loading 10.6 kg, the 0.5 and 0.1 kg masses will be used to set the line pressure and will not be available if they are needed to set the differential pressure. If this situation occurs, consider adjusting the line pressure so that it is set using a whole number of kilograms, in this example 10.0 or 11.0 kg.
Page 43 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
EXAMPLES: Mass Loading
Mass loading instruction using a PG7601 and a 35 kg mass set:
12.3 kg and 32.33 g
Load:
 piston (0.2 kg)   bell (0.3 kg)   4.5 kg #1 (makeup mass)   5 kg #1  2 kg #1  0.2 kg #1  0.1 kg #1  32.33 g from trim mass set
Mass loading instruction using PG7302 and an 80 kg mass set:
77.6 kg and 10.45 g
Load:
piston (0.2 kg) bell (0.8 kg) 9 kg #1 (makeup mass) 10 kg #1 through #6 5 kg #1 2 kg #1 0.5 kg #1 0.1 kg #1 10.45 g from trim mass set
© 1998-2002 DH Instruments, Inc. Page 44
3. GENERAL OPERATION
3.7 MAIN RUN SCREEN
The PG7000 main run screen is its home display that is reached upon powering up and from which other functions and menus are accessed. It is the top level of all menu structures.
The main run screen is where PG7000 is left in normal operation. It displays the pressure defined by PG7000, Ready/Not Ready condition and a variety of other information.
The screen described below is called the MAIN run screen. The SYSTEM and AMBIENT screens
(see Sections 3.9.5 and 3.9.6) are also run screens in the sense that all the other functions may be accessed directly from them and pressure or mass entries may be made from them. See Section 3.8 for a description of PG7000’s main menu/function structure.
1
prvPRESSURE1 unit a G h ±N.N mm NN.NNNNN kg
8
1. <prv>: Three Ready/Not Ready indication characters (from left to right: piston position, piston rotation, vacuum reference) (see Section 3.4). Each character indicates as follows:
<p>: Piston Position Ready/Not Ready. <*> when Ready, <> when Not Ready due to piston above measuring zone, <> when Not Ready due to piston below measuring zone, <?> if piston position not available or out of range. Flashes if condition is Not Ready and piston is floating (see Section 3.4.1). Indicates Not Ready when automated pressure generation is adjusting pressure.
<r>: Piston Rotation Ready/Not Ready. <*> when Ready, <<> when Not Ready due to piston rotation rate too low or motorized rotation engaged, <>> when Not Ready due to piston rotation too high, <?> if piston position not available or out of range. Flashes if condition is Not Ready and piston is floating. (see Section 3.4.2).
<v>: Vacuum Reference Ready/Not Ready (PG7601 only). <*> when Ready, <v> if Not Ready due to vacuum not below ready limit. Flashes if condition is Not Ready and piston is floating (see Section 3.4.3).
2. <PRESSURE1>: Numerical value and sign of the pressure defined by PG7000 with current mass loaded on current piston when all Ready/Not Ready indication characters indicate Ready.
4
3
5
6
3. <unit>: Current pressure unit of measure (see Section
3.9.3).
4. Current measurement mode. <a> for absolute, <g> for gauge, <d> for differential or high line differential (see Section 3.9.4).
5. Automated pressure generation status. <G> if automated pressure generation is ON. The <G> flashes if automated pressure generation is ON and active, blank if automated pressure generation is not ON (see Section 3.9.9).
6. DUT head correction status. <h> if a head correction is currently being applied, blank if head height is zero (see Section 3.9.7).
7. <NN.NNNNN kg>: Current mass load in actual mass (assuming mass loading instructions have been followed and/or mass loading entries are correct (see Section 3.6).
8. <± N.N mm>: Current piston position in millimeters from midstroke position. Positive values are above midstroke, negative values below. Indicates < ---- > if piston position not available or out of range (see Section 3.5).
When a number is too large to display in the allocated
screen space, PG7000 displays <********> or <OVERFLOW>.
PG7000 has a screen saver function that causes the
display to dim if NO key is pressed for 10 minutes. Pressing a key restores full power to the display. The screen saver activation time can be changed or screen saving can be completely disabled (see Section 3.4.5.1).
Page 45 © 1998-2002 DH Instruments, Inc.
3. GENERAL OPERATION
r
3.8 GENERAL FUNCTION/MENU FLOW CHART
Local operator interface with PG7000 is provided by PG Terminal keypad and display. Normal PG7000 operation is organized around run screens from which functions and menus are accessed. The run screens include:
MAIN run screen: Displays Ready/Not Ready, defined pressure, piston position and mass load.
(2) SYSTEM run screens: Display piston position, rotation, temperature and reference vacuum
(PG7601 only).
AMBIENT run screen: Displays ambient pressure temperature, relative humidity and local gravity. The flow chart below outlines the operating protocol of the run screens and associated key presses.
POWER
UP
or
RESET
INTRO SCREEN
5 SEC
DELAY
ESC
ESC
TO PREVIOUS RUN SCREEN
ESC
MAIN RUN SCREEN
SYSTEM
SYSTEM 1
RUN SCREEN
+/-
SYSTEM
o
SYSTEM 2
RUN SCREEN
RES
ENT SPECIAL SETUP
P-C UNIT MODE SYSTEM
AMBIENT
AMBIENT
RUN SCREEN
OTHER FUNCTION KEYS
HEAD
Figure 9. Run Screen Flow Chart
ROTATE
ESCESC
AMBIENT
GEN
Page 46 ©1998-2002 DH Instruments, Inc.
3. GENERAL OPERATION
3.9 DIRECT FUNCTION KEYS
3.9.1 DIRECT FUNCTION KEYS SUMMARY
Local operator interface with PG7000 is provided by PG Terminal keypad and display. To minimize the use of multi-layered menu structures, the keypad’s numerical keys also provide direct access to the most commonly used functions. The function accessed is labeled on the bottom half of the each key. Direct function keys are active whenever PG7000 is in a run screen (MAIN, SYSTEM or AMBIENT). Table 12 summarizes the operation of the direct function keys. Section 3.8 provides a flow chart of PG Terminal general operation. See corresponding manual Sections to 3.9.1 to 3.11.9.
It may be useful to keep a copy of Table 12 near the PG7000, especially when first
becoming acquainted with its operation.
Table 12. Summary of PG7000 Direct Function Key Operations
DIRECT FUNCTION KEYS ARE ACTIVE FROM ANY RUN SCREEN
See corresponding manual sections for full detail.
Menu of less frequently used internal functions and settings including resets, user preferences, internal calibration and remote interface setup.
Edit and select files that determine the sources of the values for the variables PG7000 uses in calculations of reference pressures.
Select pressure to mass or mass to pressure operation.
(main, ambient, system).
Activate motorized control manually (optional feature on PG7102 and PG7302). Activates when pressed, deactivates when released.
From a run screen: Access mass or pressure setting commands. From other screens: Select menu choice, enter value, confirm selection.
Turn automatic activation of motorized rotation ON/OFF (optional feature on PG7102 and PG7302).
Turn automated pressure generation/control ON/OFF. Has no effect if an automated pressure generation/control component is not part of the PG7000 system.
Set the resolution of PG7000 mass loading commands (0.01 g to 0.1 kg).
Access SYSTEM run screens (2) which display current system measurements of piston behavior, piston-cylinder temperature and reference vacuum if present. Toggles between the two screens.
Access AMBIENT run screen which displays current values of barometric pressure, ambient temperature, ambient humidity and local gravity as specified in the active SETUP file.
Adjust height of DUT fluid head correction. Set to zero to defeat head correction.
Select active piston-cylinder module (range).
Set unit of measure in which pressures are defined. Choice of units available from this key can be customized.
Set pressure measurement mode (gauge, absolute, differential).
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PG7000™ OPERATION AND MAINTENANCE MANUAL
4
3.9.2 [P-C]
PURPOSE
To view and/or change the active piston-cylinder module. In most cases, changing the piston-cylinder module is equivalent to changing the range.
[P-C] is for selecting the active piston-cylinder module only. Piston-cylinder modules can
be added and deleted and their characteristics can be edited by pressing [SPECIAL] and selecting <1PC/MS> (see Section 3.11.1).
The active mass set and mass loading bell are selected by pressing [SPECIAL] and
selecting <1PC/MS> (see Section 3.11.1).
PRINCIPLE
To make valid pressure and mass load calculations, PG7000 must know the exact characteristics of the piston-cylinder module that is currently in use. See Section 7.2 for detailed information on PG7000 pressure and mass calculations.
Most PG7000s are used with more than one piston-cylinder module. Detailed characteristics on up to 18 piston-cylinder modules are stored in files. These files can be added, deleted, viewed and edited by pressing [SPECIAL], 1pc/ms (see Section 3.11.1).
The P-C function provides rapid access, from any run screen, to viewing the piston-cylinder modules available and selecting one to be active.
OPERATION
Pressing [P-C] activates the piston-cylinder module viewing and selecting function. Pressing the [P-C] key again or [+/-] while in the P-C function steps through displays of available piston-cylinder modules.
When [P-C] is first pressed, a summary of the characteristics of the active piston-cylinder module is displayed, for example:
1. Nominal pressure to mass conversion coefficient of the piston­cylinder module that is currently selected (active). This value is calculated from the effective area of the piston-cylinder and is always in kPa (if < 1 MPa) or MPa.
2. Serial number of the active piston-cylinder module.
3. Current pressure unit of measure.
4. Nominal pressure in current pressure units resulting from loading all the mass of the active mass set.
5. Nominal pressure in current pressure units resulting from loading the piston and mass bell only.
Active 10 kPa/kg 247
0.7 to 50 psi
2
3
© 1998-2002 DH Instruments, Inc. Page 48
3. GENERAL OPERATION
4
Pressing [P-C] again or [+/-] causes the screen to step through the other available piston­cylinder modules in the sequence that they were added.
1. Nominal pressure to mass conversion coefficient of the piston-cylinder module. This value is calculated from the effective area of the piston-cylinder and is always in kPa (if < MPa) or MPa.
2. Serial number of the piston-cylinder module.
3. Current pressure unit of measure.
4. Nominal maximum pressure using the piston-cylinder module. Pressure, in current pressure units, resulting from loading all the mass of the active mass set.
5. Nominal minimum pressure using the piston-cylinder module. Pressure, in current pressure units, resulting from loading the piston and mass bell only.
Select 200kPa/kg 382 14 to 1000 psi
2
3
Pressing [ENTER] while in the P-C function causes PG7000 to select the currently displayed piston-cylinder module as the active piston-cylinder module.
Pressing [ESCAPE] while in the P-C function returns to the main run screen without changing piston-cylinder modules.
The pressure unit of measure in which the range offered by the piston-cylinder module
using the active mass set is displayed can be changed by pressing [UNIT] (see Section 3.9.3).
When the current pressure unit of measure is an altitude unit, piston-cylinder module
range is expressed in kPa if the altitude unit is meters (m) or psi if the altitude unit is feet (ft).
3.9.3 [UNIT]
PURPOSE
To specify the unit of measure in which defined pressures are expressed.
PRINCIPLE
PG7000 supports a wide variety of pressure units of measure. Internally, PG7000 always operates in Pascal [Pa] (the SI unit of pressure). Values of pressure are represented in other units by the application of conversion factors to convert from Pascal. See Section 7.1.1 for Unit of Measure Conversions.
The pressure unit of measure selection (e.g., psi, kPa, etc.) is separate from the pressure measurement mode selection (gauge, absolute or differential). See Section 3.9.4 for information on changing the measurement mode.
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PG7000™ OPERATION AND MAINTENANCE MANUAL
OPERATION
To change the pressure unit of measure, press the [UNIT] function key from any run screen. The display is (default units depend on model):
1kPa 2MPa 3Pa 4bar 5psi 6kcm2
The cursor is on the number corresponding to the active unit. To change the pressure unit, select the desired unit. The display returns to the previous run screen with the selected unit active.
If the pressure unit selected is inWa, the reference temperature for water density must be specified. When inWa is selected as the unit, the next display is:
Select inWa ref temp
° C20°°C20F
4
Select the desired reference temperature for water density using the [] or [] key to move the cursor. Pressing [ENTER] returns to the main run screen with inWa based on water density at the selected reference temperature as the active pressure unit. The current inWa reference temperature can be viewed by observing the position of the cursor in the reference temperature screen.
See Section 7.1 for tables of the pressure unit of measure conversion factors used by
PG7000.
The UNIT function provides rapid access to a choice of up to six units. The choice of
units can be customized from a wider selection by the user (see Section 3.9.3.1). The default units of the UNIT function depend on the PG7000 model. The default units are:
PG7102 and PG7601: 1kPa 2MPa 3Pa 4bar 5psi 6kcm2
PG7202 and PG7302: 1MPa 2kPa 3bar 4psi 5kcm2
To restore the default UNIT function settings, use the Unit Reset (see Section 3.11.9.2).
Certain internal and/or metrological functions (e.g., vacuum reference pressure) are
always represented in Pascal [Pa], regardless of the active pressure unit of measure.
When the current pressure unit of measure is an altitude unit, atmospheric pressure in
the AMBIENT run screen is expressed in kPa if the altitude unit is meters (m) or psi if the altitude unit is feet (ft).
© 1998-2002 DH Instruments, Inc. Page 50
3. GENERAL OPERATION
3.9.3.1 CUSTOMIZING PRESSURE UNITS AVAILABLE UNDER THE UNIT FUNCTION
PURPOSE
To customize the selection of pressure units that are available for selection from the [UNIT] function key.
PRINCIPLE
The UNIT function provides a choice of different pressure units of measure depending on the PG7000 model. The units that are available by default are those indicated in the Note in Section 3.9.3. However, PG7000 supports many other pressure units of measure. Other units can be made available for selection and units can be deleted by customizing the UNIT function. This allows PG7000 to offer a very wide selection of units while simplifying day to day operation. The typical user will customize the [UNIT] function key to support the six most commonly used units.
OPERATION
To customize the [UNIT] function key, from the main run screen press [SETUP] and select <2PresU>. The display is:
1. The UNIT function key menu is to be changed.
Enter the number of the unit position that you would like to change. The display becomes:
Set up user unit #6
Unit #6 1SI 2other 3altitude 4user
Select the desired pressure unit category. SI units include units based on SI such as mmHg. Select the desired unit from the unit list (see Table 13).
Table 13. Pressure Units of Measure Available
<1SI> <2Other> <3altitude>* <4User>**
<1Pa> <2Kpa> <3MPa> <4mbar> <5bar> <6mmHg> <7mmWa>
* <3altitude>: PG7601 in absolute by vacuum mode only. Not available in PG7102, PG7202 and PG7302.
** <4user>: User defined unit. As there are no altitude units on PG7102, PG7202 and PG7302, user is <3user>.
<1psi> <2psf> <3inHg> <4inWa> <5kcm2> <6none>
<1m> <2ft>
<1user>
The UNIT function display is not required to display six units. To delete the current unit from the UNIT screen and show no unit, select <2other>, <6none> for that unit number.
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PG7000™ OPERATION AND MAINTENANCE MANUAL
If <4user> was selected, the user unit must be defined. The display is:
1. Entry field.
Enter the number of user units per Pascal [Pa] in the entry field. Pressing [ENTER] defines the user unit and returns to the <Set up unit #> screen.
See Section 7.1.1 for the pressure unit of measure conversion factors used
by PG7000.
The user defined unit can be assigned a user defined label using the UDU
remote command (see Section 4.3.4.2).
3.9.4 [MODE]
PURPOSE
Define user unit:
1.000000 Units/Pa
To specify the measurement mode (gauge, absolute, differential) in which PG7000 defines reference pressures.
Pressure measurement mode and unit of measure are not the same thing.
See Section 3.9.3 for information on the pressure unit of measure.
PRINCIPLE
Pressure defined relative to absolute zero or vacuum is generally referred to as absolute pressure.
Pressure defined relative to atmospheric pressure is generally referred to as gauge pressure, with pressure below atmosphere called negative gauge pressure.
Pressure defined relative to another pressure that may be, but is not necessarily atmospheric pressure, is generally referred to as differential pressure.
PG7000s (depending on the model) can define absolute, gauge, negative gauge and differential pressures. These are referred to as measurement modes.
The specific PG7000 measurement modes are as follows:
gauge: Defines gauge pressure by leaving the PG7000 mass load open to atmosphere. This measurement mode is supported by all PG7000 models. It does not allow negative gauge pressures. The minimum gauge pressure is the pressure resulting from loading the combined mass of the piston and the bell on piston-cylinder effective area.
absolute by adding atmospheric pressure (absolute by ATM): Defines absolute pressure by defining a pressure in the same manner as in gauge mode and adding the value of atmospheric pressure measured by a barometer. This measurement mode is supported by all PG7000 models. The barometer can be PG7000’s on-board sensor or a remote RS232 barometer. The uncertainty on the value of atmospheric pressure measured by the barometer must be considered but this value can become relatively small as pressure goes up. For example, if using a ± 0.01 % barometer, the added uncertainty at 1 MPa (150 psi) is 10 ppm.
© 1998-2002 DH Instruments, Inc. Page 52
3. GENERAL OPERATION
This mode is more convenient and less costly than absolute by vacuum since no vacuum reference needs to be established. However, it does not allow absolute pressures under atmosphere and the minimum absolute pressure is atmospheric pressure plus the pressure resu lting from loading the combined mass of the piston and the bell on the piston-cylinder effective area.
absolute by vacuum (absolute by vac) (PG7601 only): Defines absolute pressure by measuring relative to an evacuated bell jar. This mode is time consuming as the vacuum under the bell jar must be made and broken to adjust the mass load for each pressure to be set. This mode is required for setting absolute pressures under atmospheric pressure and for lowest uncertainty under about 1 MPa (150 psi).
differential (dif) (PG7601 only): Defines differential pressures at an absolute static pressure between vacuum and two atmospheres by defining an absolute pressure relative to an evacuated bell jar and subtracting static pressure monitored by a digital pressure indicator. An offsetting technique ensures that only on the digital indicator’s resolution and very short term repeatability influence the measurement results. Allows positive and negative differential pressure (including gauge pressures) with one common hardware setup. Covers pressures very near and at zero without limitations due to piston-cylinder size and mass loads (see Section 3.9.4.1).
high line differential (Hldif) (PG7102 and PG7202 only): Defines differential pressures and at gauge static pressure between the lowest gauge pressure supported by the piston-cylinder and the maximum gauge pressure supported by the piston­cylinder. Requires the use of a PG7202 or PG7102 as the “reference” and a second gas operated PG7000 as the “tare”. Differential pressures are defined by setting a common line pressure on both PG7000s and then adding the differential pressure to the reference PG7000 (see Section 3.9.4.2).
OPERATION
To change the pressure measurement mode, press [MODE] from any run screen. The resulting display depends on the PG7000 Model:
The cursor is on the number corresponding to the current measurement mode.
Measurement mode: 1gauge 2abs 3HLdif
PG7 1 0 2 [M OD E] S c re e n P 73 0 2 [M OD E] S c re en PG 7 6 0 1 [M OD E] S c re e nG
Measurement mode: 1gauge 2absolute
Measurement mode: 1g 2avac 3aatm 4dif
For PG7102, PG7202 and PG7302, selecting <2absolute> accesses absolute by ATM mode (see PRINCIPLE above).
For PG7102 and PG7202, selecting <3Hldif> accesses high line differential mode (see PRINCIPLE above and Section 3.9.4.2).
For PG7601, selecting <2avac> accesses absolute by vacuum mode. Selecting <3aatm> accesses absolute by ATM mode. Selecting <4dif> accesses differential mode (see PRINCIPLE above and Section 3.9.4.1).
Making a measurement mode selection returns to the previous run screen with the selected mode active.
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PG7000™ OPERATION AND MAINTENANCE MANUAL
3.9.4.1 DIFFERENTIAL MEASUREMENT MODE (PG7601 ONLY)
PURPOSE
To define gauge pressures near and under atmospheric pressure that cannot be covered in conventional gauge mode; to define pressures at a static pressure near atmospheric pressure but other than atmospheric pressure.
Differential mode operation is only supported by PG7601. Differential mode
operation requires that the PG7601 SETUP AtmP selection be for an external barometer connected to COM2 (see Section 3.10, 3.11.5.4). Differential mode operation also requires the PG7000 Differential Mode Interconnections Kit P/N 401581, which includes the Differential Mode Controller.
PRINCIPLE
Differential mode is designed to allow PG7601 to define pressures which piston gauges have typically not covered or for which they have been difficult to use. This includes positive and negative gauge pressures right around zero, for example ± 2.5 kPa (10 in. H2O); as well as low differential pressures at low absolute static pressures, for example 0 to 2.5 kPa (20 Torr) at 15 kPa absolute (2.2 psia) static pressure.
The principal of differential mode is to define a differential pressure as the difference between an absolute pressure relative to vacuum and a second absolute pressure (the static pressure) measured by a precision Reference Pressure Monitor (RPM). An offsetting procedure “tares” the RPM so that the uncertainty contributed to the differential pressure by the RPM’s measurement is a function of the RPM resolution and short term repeatability rather than its absolute accuracy and long term stability.
For differential mode operation, the static pressure is set to the desired value as measured by the RPM (atmospheric pressure for gauge pressure measurements). Then RPM offset at the static pressure is determined by applying the static pressure as defined by the PG7601 following:
offset = PGRPMstart - RPMindicate
RPM
Where:
RPMoffset
PGRPM
RPMindicate
start
= RPM indication of static pressure
(atmospheric if gauge mode)
= Pressure applied by PG7601 to RPM
(nominally equal to RPM
=
RPM reading when PGRPMstart is applied to RPM test port
start)
Once the RPM offset has been determined, differential pressures are defined by subtracting the static pressure measured by the RPM from an absolute pressure defined by the PG7601 following:
Where:
© 1998-2002 DH Instruments, Inc. Page 54
Pgdif Pgabs RPM
current
dif = PGabs - RPMcurrent - RPMoffset
PG
= Differential pressure defined by PG7601 = Absolute pressure defined by PG7601 = Current RPM indication of static pressure
3. GENERAL OPERATION
For differential mode operation, the PG7000 Differential Mode Interconnections Kit should be used to provide the DUT high and low test connections and support the RPM offsetting procedure (see Figure 9 and Section 3.9.4.1). A precision Reference Pressure Monitor, such as a DHI RPM, must be selected for the AtmP source in SETUP (see Section 3.10, 3.11.5.4).
PG7601 differential measurement mode manages the data acquisition and handling to support differential mode operation without operator effort. Differential mode operation requires setting the static pressure at which differential measurements are to be made and regular determination of the RPM offset. These functions are supported under [MODE], <4dif>.
1. PG/STATIC P CONTROL Port
2. PG Port
3. TEST HIGH Port (Quick Connection)
4. TEST LOW Port (Quick Connection)
5. 1/8 in. NPT F or 4T Quick Connector
6. STATIC P Port
7. STATIC P SUPPLY Port
8. CONTROL SELECTION Valve
9. PG SHUTOFF Valve
10. TEST BYPASS Valve
11. Reference Pressure Monitor (RPM) (Optional)
12. STATIC P SELECTION Valve
13. Static Pressure Exhaust (Internal)
DHI Technical Note 9940TN02 provides more detailed information on
Page 55 © 1998-2002 DH Instruments, Inc.
Figure 10. Differential Mode Controller Schematic
differential mode principles and includes a complete uncertainty analysis. Consult DHI or visit www.dhinstruments.com.
PG7000™ OPERATION AND MAINTENANCE MANUAL
OPERATION
To select differential mode operation and access differential mode functions press [MODE] and select <4dif>.
Differential mode operation includes:
Selecting differential mode, setting static pressure and finding the RPM offset (see Section 3.9.4.1, Selecting Differential Mode, Setting Static Pressure, Finding RPM Offset (<1run>).
Operating in differential mode (see Section 3.9.4.1, Operating In Differential Mode).
Viewing differential mode static pressure and RPM offset (see Section 3.9.4.1, Viewing Static Pressure and RPM Offset (<2view>).
Selecting Differential Mode, Setting Static Pressure, Finding RPM Offset (<1run>)
To operate in differential mode and/or execute the RPM offset determination
procedure, the AtmP selection under SETUP must be external (COM2) (see Section 3.10). If this is not the case, an error message will be displayed (<Dif mode requires COM2 AtmP SETUP>) when attempting to activate differential mode.
To select differential mode operation and/or execute the RPM offset determination procedure, press [MODE] and select <4dif>, <1run>. The display is:
1. Current value of RPM offset. Always in Pascal [Pa].
Offset: 9.03 Pa
New offset? 1no 2yes
Select <1no> to use the existing RPM offset and return the previous run screen in differential mode (see Section 3.9.4.1, Operating in Differential Mode
).
The RPM offset should be redetermined any time the static pressure value is
changed, as well as at the beginning of each calibration or test sequence. If the difference in the value of the RPM offset in subsequent determinations is < 0.1 Pa, then less frequent offset determinations may be considered.
Select <2yes> to proceed with a new determination of the RPM offset (see Section 3.9.4.1, PRINCIPAL. The display is:
Set RPM P & [E NT ER]
1. Current pressure reading of the RPM in the current units of.
96.57785 kPa a
© 1998-2002 DH Instruments, Inc. Page 56
3. GENERAL OPERATION
Table 14. Valve Settings for Setting Differential Mode Static Pressure
VALVE VALVE SETTING
Control Selection Static P PG Shutoff Closed Test Bypass Open Static P Selection Off
If static pressure is atmospheric pressure VENT or OFF
With the Differential Mode Controller valves (see Figure 9) set as indicated in Table 14, use the systems’ pressure control component (MPC1 or RPM1) to set the desired static pressure value as read by the RPM.
If the desired static pressure is atmospheric pressure (for example, for low gauge and negative gauge differential pressures), set the STATIC P SELECTION valve to VENT.
If a REFERENCE VOLUME is connected to the STATIC P port and the desired static pressure is less than atmospheric pressure, consider setting the STATIC P SELECTION VALVE to SUPPLY. This will connect the pressure setting vacuum source directly to the reference volume and reduce pull down time.
Be sure the TEST BYPASS valve is in the OPEN position before adjusting the
static pressure. Failure to do so will cause differential pressure to be generated across the HIGH and LOW TEST ports which may overpressure the DUT.
When the static pressure, as indicated by the RPM, has been set to the desired value, press [ENTER]. PG7000 reads the RPM and calculates the mass to load on
Load mass & vac:
9.2 kg & 32.47 g
PG7000 to set the pressure value indicated by the RPM. The display is:
This is the standard nominal mass loading in instruction display of pressure to mass mode (see Section 3.9.11.1). The mass loading instruction is always given with 0.01 g resolution regardless of the current mass loading resolution setting (see Section 3.9.10). Load the mass value following PG7000 mass loading protocol (see Section 3.6).
Set the PG7000 Differential Mode Controller (see Figure 9) to apply the pressure defined by the PG7000 to the RPM (see Table 15).
Table 15. Valve Settings to Apply PG7000 Pressure
to the RPM for Differential Mode Offsetting
VALVE VALVE SETTING
Control Selection PG PG Shutoff Open Test Bypass Open Static P Selection Off
If static pressure is atmospheric pressure VENT or OFF
Page 57 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Once the valves have been properly set and the mass has been loaded, install the bell jar and establish vacuum under the bell jar. Then press [ENTER]. The display is:
1. Current pressure reading of the RPM in the current units of measure.
2. Standard main run screen piston position indication (see Section 3.7).
3.
Current RPM offset (pressure applied by PG7000 - RPM indication). Indicates ******* if the value is > 9999.99 Pa. Pressure unit of measure is always Pascal [Pa].
Float and rotate the PG7000 piston. When the PG7000 is ready (see Section 3.4), press [ENTER]. Wait about 6 seconds while the PG7000 takes and averages multiple readings. The display is:
<<* 99.9785 kPa a h
- 3.5 Off: -7.89 Pa
3
2
1. RPM offset currently in use.
2. New RPM offset just measured.
Old offset: -7.72 Pa New offset: -7.89 Pa
2
To record the new RPM offset and go to the previous run screen in differential mode with the new RPM offset active, press [ENTER].
To return to the <New offset?> screen, press [ESCAPE]. See Section 3.9.4.1, Operating in Differential Mode
, for information on differential
mode operation.
The value of the RPM offset typically should be inside of ± 20 Pa. An RPM
offset value outside of this range may indicate a poorly calibrated RPM or a problem with the offset determination procedure.
The difference between the RPM offset at the beginning and at the end of a
test will be reflected as zero drift of the differential pressures defined during the test. To quantify this value, perform the RPM offset procedure at the beginning and at the end of a test and evaluate the difference between the starting and ending RPM offset values.
© 1998-2002 DH Instruments, Inc. Page 58
3. GENERAL OPERATION
Differential mode is often used to calibrate DUTs with very low differential
pressure ranges. These can easily be overpressured and damaged by inadvertently applying excessive pressure to one port. OPEN the MPC1-D BYPASS valve to zero the differential across the DUT when there is a risk of overpressure.
Operating in Differential Mode
From a practical standpoint, operating in differential mode is nearly identical to operating in absolute by vacuum mode (see Section 3.9.11). Vacuum under the bell jar must be broken to make mass load changes and reestablished to set a pressure.
Operation is in either pressure to mass or mass to pressure mode (see Section 3.9.12).
To operate in differential mode, set the PG7000 Differential Mode Controller (see Figure 9) to apply pressure defined by PG7000 to the high side of the DUT (see Table 16).
Table 16. Valve Settings for Operating in Differential Mode
VALVE VALVE SETTING
Control Selection To adjust pressure under PG7000 piston: PG
To adjust static pressure: STATIC P
PG Shutoff Piston is floating or near floating: OPEN
Any other time: CLOSED
Test Bypass To make differential pressure measurements: CLOSED
To set or check DUT zero: OPEN
Static P Selection OFF
If static pressure is atmospheric pressure: VENT or OFF
For the highest quality differential mode measurements, use consistent
conditions for static pressure and PG7000 vacuum reference pressure at each point. Set the PG7000 Differential Mode Interconnections Kit CONTROL valve to STATIC P to readjust the static pressure to the same value at each point if necessary.
Page 59 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Typical Differential Mode Operational Sequence
See Figure 9 for a schematic of the Differential Mode Controller and its valves. Set RPM offset at desired static pressure (see Section 3.9.4.1, Selecting
Differential Mode, Setting Static Pressure, Finding RPM Offset (<1run>)).
Select pressure to mass or mass to pressure mode (see Section 3.9.12). Put the Differential Mode Controller PG SHUTOFF valve in CLOSED
position.
If desired, read DUT output at zero differential pressure with
TEST BYPASS valve open. Put TEST BYPASS valve in CLOSED position. If desired, put CONTROL valve in STATIC P position and use system control component to adjust static pressure to starting value.
Press [ENTER] and enter a pressure or mass value. Load mass as instructed
on PG7000.
Install bell jar on PG7000, shut the PG7000 vacuum vent valve, open
vacu um reference shutoff valve. Wait for vacuum under bell jar to reach Ready condition.
Put CONTROL valve in PG position and use system control component to
float PG7000 piston. Slowly put PG SHUTOFF valve into OPEN position. Readjust pressure to float the PG7000 piston if necessary.
If desired, put CONTROL valve in STATIC P position and use system control
component to adjust static pressure to starting value.
When PG7000 indicates Ready on all Ready/Not Ready indicators, take
DUT reading at differential pressure indicated on the top line of the PG7000
display. Slowly put PG SHUTOFF valve in CLOSED position. Shut vacuum reference shutoff valve, open vacuum vent valve. Wait for
pressure under bell jar to return to ambient. Remove bell jar. Repeat Steps  through for each desired differential pressure point.
© 1998-2002 DH Instruments, Inc. Page 60
3. GENERAL OPERATION
Setting Zero Differential Pressure
See Figure 9 for a schematic of the Differential Mode Controller and its valves. Zero differential pressure can be set by PG7000 or simply by setting the
Differential Mode Controller TEST BYPASS valve to the OPEN position which connects the HIGH and LOW TEST ports together. The TEST BYPASS valve OPEN position is a “true” zero. The zero differential pressure value set by PG7000 has the same uncertainty as any other differential pressure point (see Section 1.2.4.1). Comparing the DUT reading at zero set by TEST BYPASS in the OPEN position and at zero set by PG7000 in differential mode like any other differential pressure, can help quantify the quality of the current RPM offset value. If the difference between the two zero readings is excessive, the RPM offset value should be redetermined (see Section 3.9.4.1, Selecting Differential Mode, Setting Static Pressure, Finding RPM Offset (<1run>)). Also, consider correcting all the DUT readings by the difference in the zero reading found in the two different conditions to correct for the defect in the RPM offset.
Viewing Static Pressure and RPM Offset (<2view>)
To view the current RPM offset and the static pressure value at which the offset was recorded, press [MODE] and select <4dif>, <2view>. This display is:
1. RPM offset value that is currently active.
2. PG7000 pressure at which RPM offset was recorded.
Offset: -6.33 Pa
@99.8755 kPa a
2
Press [ESCAPE] to return to the <Differential mode:> menu. Press [ENTER] to return to the previous run screen.
3.9.4.2 HIGH LINE DIFFERENTIAL MEASUREMENT MODE (PG7102 AND PG7202 ONLY)
PURPOSE
To define differential pressures at elevated line pressures up to 11 MPa (1 600 psi) with PG7102 or 110 MPa (16 000 psi) with PG7202.
High line differential (HL dif) mode operation is only supported by PG7102
and PG7202. HL dif mode operation requires the use of a PG7102 or PG7202 and another gas operated PG7000 (PG7102, PG7202 or PG7601) in tandem. Both PG7000s must have nominally identical piston-cylinders and one of the PG7000s must have a “tare” piston-cylinder. The HL dif mode setup for pressure up to 110 MPa (1 600 psi) normally also includes an MPC1-D-1000 or MPC1-D-3000 manual pressure controller and the PK-7100-MPCD-DIF Interconnections Kit P/N 401645. The HL dif mode setup for pressure greater than 110 MPa uses GPC1 and custom interconnecting hardware.
Page 61 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
PRINCIPLE
DHI Technical Note 0080TN03 provides more detailed information on high
line differential mode principles including a complete uncertainty analysis. Consult DHI or visit our website, www.dhinstruments.com
High line differential mode is designed to allow a PG7102 or PG7202 and a second gas operated PG7000 to be used together to define differential pressures rela tive to line pressures significantly above atmospheric pressure. This capability is most often used to test or calibrate differential pressure devices designed to operate at elevated line pressures under their normal operating line pressure conditions.
The main challenge of defining differential pressures at elevated line pressures comes from the very high ratio of line pressure to differential pressure. Relatively small errors and instabilities in the line pressure are very large relative to the differential pressure.
The principal of high line differential mode is to “crossfloat” two PG7000 gas operated piston gauges so that they define a common line pressure. After the crossfloat is completed, a BYPASS valve is closed isolating one PG7000 from the other. The “tare” PG7000 (PG7102, PG7202 or PG7601) maintains the line pressure. Mass is added to the “reference” PG7000 to define differential pressures “on top of” the line pressure. The very high precision of the PG7000 gas operated piston gauges allows them to set and maintain a common line pressure with uncertainty much lower than the overall measurement uncertainty on either piston gauge. The two PG7000s are crossfloated at the line pressure prior to making differential measurement to minimize the contribution of line pressure errors to differential pressure. The crossfloating procedure consists of making mass adjustments on the tare PG7000 so that both pistons, when connected together at the line pressure, fall at their “natural” drop rate. PG7000’s embedded piston fall rate measurements and calculations capabilities are used to assist the operator in performing the crossfloat.
to obtain a copy.
The PG7000 that is used only to maintain the line pressure on the low side of the device under test (DUT) is designated the tare PG7000. The tare PG7000 is a standard PG7102, PG7202 or PG7601 but it is normally used with a tare piston­cylinder and a tare mass set (a standard piston-cylinder and mass set may also be used). A tare piston-cylinder effective area is entered as the nominal effective area and its characteristics include k(P), which must be entered in the piston-cylinder definition file (see Section 3.11.1.1). A tare mass set has the same configuration as a standard mass set but the exact values of the masses are not measured and the mass set is set up using nominal values for each mass measured value (see Section 3.11.1.6). The tare piston mass is adjusted to be slightly under the nominal piston mass of 200 g. This assures that the tare side will always be the light side when crossfloated with the reference side. If a tare piston-cylinder and mass set is not used on the tare PG7000, the tare side may not be the light side in a crossfloat. In this case, the tare mass load on the reference side should be increased slightly (generally < 1 g) to ensure that it is heavier, taking care not to confuse the added tare mass with the subsequent differential mass load.
The PG7102 or PG7202 that is used to apply the added pressure to create the differential pressures on the high side of the DUT is designated the reference PG7000. The reference PG7000 is a standard PG7102 or PG7202 with a standard piston-cylinder and mass set. The reference must be a PG7102 or PG7202, the tare may be a PG7102, PG7202 or a PG7601.
© 1998-2002 DH Instruments, Inc. Page 62
3. GENERAL OPERATION
The tare and reference PG7000s must have nominally identical piston-cylinders. The two PG7000s operate together with the reference acting as “master” and the tare as “slave”. For communications between the two to occur, COM2 of the reference must be connected to COM1 of the tare with a valid RS232 cable and proper settings must be made on both interfaces (see Section 3.11.5.1).
For high line differential mode operation up to 11 MPa (1 600 psi), an MPC1-D and the PK-7100-MPCD-DIF Interconnections Kit P/N 401645 should be used to provide the DUT high and low test connections and support line pressure and differential pressure setting procedures (see Figure 10). For operation at pressure greater than 11 MPa, GPC1 and custom interconnecting hardware are used in a functionally similar setup.
PG7000 high line differential measurement mode manages the data acquisition and handling necessary to support differential mode operation. Differential mode operation requires setting the line pressure including crossfloating the two PG7000 piston gauges and then setting differential pressures at the line pressure. These two independent operations are supported under [MODE], <3HLdif>, <1run>.
High line differential mode relies upon the very high sensitivity of PG7000
gas operated piston-cylinders to set and stabilize low differential pressures relative to very high line pressures. To meet the full performance potential of PG7000 high line differential mode operation, external influences on the piston gauges must be minimized. Air currents and vibrations are the most significant possible influences. Do not operate near an active air conditioning or heating duct, avoid opening and closing doors or any movement of personnel around the system. Consider putting the PG7000s in an electrostatic free enclosure if the environment cannot be adequately controlled.
See Section 7.2.1 for information on the exact calculations used by PG7102
and PG7202 to obtain the differential pressures defined in high line differential mode.
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PG7000™ OPERATION AND MAINTENANCE MANUAL
1. Tare PG7000 (PG7102, PG7202, or PG7601)
2. Differential Device Under Test (DUT
3. Reference PG7000 (PG7102 or PG7202)
4. MPC1-D or other INLET Valve
Figure 11. High Line Differential Mode Schematic
5. MPC1-D or other Hi Variable Volume (Hi VV)
6. MPC1-D or other VENT Valve
7. MPC1-D or other HI/LO BYPASS Valve
8. MPC1-D or other Lo Variable Volume (Lo VV)
DHI Technical Note 0080TN03 provides more detailed information on high
line differential mode principles using PG7102 and PG7601 piston gauges and includes a complete uncertainty analysis. Consult DHI or visit our website, www.dhinstruments.com to obtain a copy.
OPERATION
To select high line differential mode operation and access differential mode functions press [MODE], <3HLdif> on the reference PG7102 or PG7202.
When operating in high line differential pressure mode, the reference
PG7000 is “master” and the tare PG7000is “slave”. All operator interaction is with the PG Terminal of the reference PG7000. The tare’s display is for information only. The tare PG7000 keypad is inactive.
High line differential mode operation includes:
Entering differential mode (see Section 3.9.4.2, Entering High Line
Differential Mode ([MODE], <3HLdif>, <1run>)).
Setting a line pressure (see Section 3.9.4.2, Setting a Line Pressure
([MODE], <3HLdif>, <1run>, <2yes>)).
© 1998-2002 DH Instruments, Inc. Page 64
3. GENERAL OPERATION
<
Setting differential pressures at a high line pressure (see Section 3.9.4.2,
Setting Differential Pressures at a High Line Pressure
).
Viewing current line pressure and natural fall rates for the line pressure (see
Section 3.9.4.2, Viewing Line Pressure, Starting Piston-Cylinder
Temperatures and Natural Piston Fall Rates ([MODE], <3HLdif>, <2view>).
Entering High Line Differential Mode ([MODE], <3HLdif>, <1run>) To enter high line differential mode, press [MODE] ,<3HLdif>, <1run> on the
reference PG7000’s PG Terminal.
The reference PG7000 initializes high line differential mode. To su cces s f u lly e n t e r high line differential mode the reference PG7000 must be able to communicate with the tare PG7000, the piston-cylinders in both PG7000s must be nominally identical and the piston-cylinder in the tare PG7000 must have a non-zero value for k(P) in its piston-cylinder module file. When initializing high line differential mode, the reference PG7000 tests for these conditions and provides error messages as follows:
<Cannot find PG7000 on COM2>: The reference PG7000 must be
connected to COM2 of the tare PG7000 using a valid RS232 cable and both interfaces must be properly set so that communications between the two PG7000s can occur (see Sections 3.11.5.1, 3.11.5.4). If the reference is unable to communicate with the tare, this error message is displayed. If this error message is observed, correct the communications problem and retry (see Section 3.11.5.1).
<T & R PCs not a pair, cannot run HLdif>: The piston-cylinder modules in
the two PG7000s must be nominally identical (have the same nominal mass to pressure conversion coefficient). If the reference PG7000 finds the two piston-cylinder modules to be different, this error message is displayed. If this error message is observed, correct the situation by changing piston­cylinder selection or adjusting one piston-cylinder’s definition (see Sections 3.9.2,
3.11.1.2).
<No T PC in T PG7000, cannot run HLdif>: The piston-cylinder module
selected in the tare PG7000 must have a non-zero value for k(P) in the active piston-cylinder module file. If the k(P) value is zero, this error message is displayed. If this error message is observed, correct the situation by providing a non-zero value for k(P) in the piston-cylinder module file of the tare piston-cylinder (see Section 3.11.1.2).
After high line differential mode is initialized, the display of the tare PG7000 is:
1. Standard Ready/Not Ready indicators for the tare PG7000.
2. Last line pressure set in the pressure unit of measure
that was active when the line pressure was set. The unit of measure remains the same, even if the reference PG7000’s unit of measure is changed, until a new line pressure is set.
3. Label indicating that the mass load includes whatever trim masses were loaded on the tare piston in the crossfloating process to reach equilibrium.
4. Tare mass load for the last line pressure set.
5. Current piston position of the tare PG7000.
2
1000.70 psi LP
- 3.7 30.3 kg + trim
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PG7000™ OPERATION AND MAINTENANCE MANUAL
While in high line differential pressure mode, the tare PG Terminal keypad is inactive.
After high line differential mode is initialized, the display of the reference PG7000 is:
1. Current (last set) value of line pressure in current
pressure unit of measure.
Line P: 1000 psi
New line P? 1no 2yes
Select <1no> to use the existing line pressure settings and return to the previous run screen in high line differential measurement mode (see Section 3.9.4.2,
Setting Differential Pressures at a High Line Pressure
).
Select <2yes> to set a new line pressure value or repeat the line pressure setting procedure at the current line pressure value (see Section 3.9.4.2, Setting a Line Pressure ([MODE], <3HLdif>, <1run>, <2yes>)).
The line pressure setting procedure must be executed each time the line
pressure is changed and should be executed at the beginning of each differential pressure calibration sequence even if the line pressure is the same as the line pressure previously used. Select <2yes> to go to the line setting procedure.
Setting a Line Pressure ([MODE], <3HLdif>, <1run>, <2yes>)
To meet the full performance potential of PG7000 high line differential mode
operation, external influences on the piston gauges must be reduced or eliminated. Air currents and vibrations are the most significant possible influences. Do not operate near an active air conditioning or heating duct, avoid opening and closing doors or any movement of personnel around the system.
Leaks at any point in the test system are highly detrimental to
Setting a line pressure has two steps: Setting the line pressure and determining the natural fall rates of the tare and
reference pistons.
Performing a crossfloat of the pistons to reach equilibrium and minimize
differential pressure zero offset.
To set a line pressure press [MODE], <3HLdif>, <1run>, <2yes> on the reference PG7000’s PG Terminal. The display is:
1. Edit field for entry of desired line pressure value in
current pressure unit of measure. Defaults to last value used.
© 1998-2002 DH Instruments, Inc. Page 66
measurement results in high line differential mode. Thoroughly leak check the system before operation and correct any leaks detected.
Target line P: 1000 psi
3. GENERAL OPERATION
Values of line pressure are always entered and displayed in gauge mode
(i.e., relative to atmospheric pressure). Line pressure mass loading instructions are always given with 0.1 kg resolution. The minimum line pressure is the pressure resulting when the mass of the piston + mass bell is loaded.
Enter the desired line pressure value. The next display indicates the mass to load to set the line pressure.
Load nominal mass on
T & R: 33.3 kg
This display corresponds to the standard mass loading instruction display of pressure to mass mode (see Section 3.9.11.1). The mass loading instruction is always given with 0.1 kg resolution regardless of the current mass loading resolution setting (see Section 3.9.10). Load the indicated mass on both the tare and reference PG7000s following PG7000 mass loading protocol using main and fractional masses only (do not use trim masses) (see Section 3.6). Press [ENTER] when ready.
Line pressure mass instructions are always given with 0.1 kg resolution. This is
to preserve the smaller masses for setting the differential pressure. The differential pressure mass loading instructions follow conventional PG7000 mass loading protocol using the masses that remain after the line pressure has been set. It may be necessary to select the line pressure value to assure that adequate masses remain to set the desired differential pressure. For example, if the line pressure requires loading 33.3 kg, a 0.2 and 0.1 kg mass will be used to set the line pressure and will not be available if needed to set the desired differential pressure. If this situation occurs, consider changing the line pressure so that it is set using a whole number of kilograms, in this example 33 or 34 kg.
The display is:
With the system’s BYPASS valve OPEN (see Figure 10), use the INLET and/or VENT valve and the high side variable volume to adjust the pressure to float the piston of the tare PG7000. This should cause the reference PG7000 piston to be at its bottom stop. Once the tare piston is floating, close the system’s BYPASS valve and press [ENTER]. The next display is:
1. Tare piston position.
2. Reference piston position.
Use the high and/or low side variable volume to set both pistons to a position just above + 1.0 mm. Ensure that both pistons are rotating. As both pistons fall through the + 1.0 position, press [ENTER]. PG7000 pauses for 5 seconds and then measures the natural fall rates of both pistons for 30 seconds.
Page 67 © 1998-2002 DH Instruments, Inc.
Open bypass, float T, Close bypass, [ENTER]
2
+1.2 mm -3.6 Set T & R to +1.0 & [ENT]
PG7000™ OPERATION AND MAINTENANCE MANUAL
2
1. Indication of tare piston position.
2. Indication of reference piston position.
3. 30 second count down.
T +1.0 mm R +1.0
Finding rates 29
3
Wait for the 30 second timer to count down while the measurements are made. Be sure not to interfere with the free movement of the piston-cylinders during the countdown. After the countdown completes, the results are displayed:
2
1. Average fall rate of the taring piston.
2. Average fall rate of the reference piston.
3. Difference between the reference and taring piston fall rates (R - T). This is the “natural fall rate difference”.
T-0.9 mm/min R-1.1
-0.2 Save 1yes 2no
3
The “natural fall rate difference” is the difference between the fall rates of
the two pistons when they are floating naturally at the line pressure. When performing the crossfloat between the pistons in the next step of line pressure setting, the objective will be to adjust the mass of the tare piston until the “crossfloat fall rate difference” measured with the system’s BYPASS valve open is equal to the “natural fall rate difference” measured with the BYPASS closed.
Select <2no> to repeat the “natural fall rate difference” measurement. Select <2yes> to accept the “natural fall rate difference” value and continue to the second step of line
Open bypass and
[ENTER] to xfloat
pressure setting which is crossfloating the two piston-cylinders. The display is:
Open the BYPASS valve and press [ENTER] to proceed with the crossfloat. The display is:
1. Tare piston position.
2. Reference piston position.
3. Difference between the “natural fall rate difference” and the “crossfloat fall rate difference” in mm/min. This is the “equilibrium fall rate”.
T-1.2 mm R+0 .5
1.2 B/P open,[ENT]
+
3
2
The “equilibrium fall rate” is the difference between the “natural fall rate
difference” and the “crossfloat fall rate difference”:
Equilibrium fall rate = (R
When the “equilibrium fall rate” is zero, the two piston-cylinders are at
nat
- T
nat
) - (R
xfloat
-T
xfloat
)
equilibrium at the line pressure.
© 1998-2002 DH Instruments, Inc. Page 68
3. GENERAL OPERATION
Crossfloat the two pistons to find equilibrium by making mass adjustments on the tare piston. Finding equilibrium is an iterative process which is assisted by PG7000. Pressing [ENTER] starts an automated fall rate measurement sequence that measures the fall rates more precisely than the real time indication. Following a 30 second countdown or when one of the pistons has moved more than 1 mm, PG7000 displays the measured “equilibrium fall rate” and suggests the mass adjustment needed on the tare piston to achieve an “equilibrium fall rate” of zero. This process can be repeated as many times as desired.
If a standard piston-cylinder and mass set (rather than a tare piston-cylinder
and mass set) is being used in the tare PG7000, the tare piston may be the heavy one at the start of the crossfloat (see Section 3.9.4.2, PRINCIPLE). In this case, rather than reduce mass on the tare PG7000, add a small amount of mass to the reference PG7000 before starting the crossfloat so that the tare piston will be the lighter one (generally < 1 g is needed). This will simplify the crossfloating procedure and subsequent differential mass loading. Be sure not to confuse the additional tare mass on the reference piston with the subsequent differential mass loads.
Using trim masses (50 g and below) from the trim mass set, adjust the mass load on the tare PG7000 to establish equilibrium (“equilibrium fall rate” near zero). When the mass adjustments are complete, close the BYPASS valve and put both pistons at a position just above 0.0 mm. Ensure that both pistons are rotating. As the pistons fall through the 0.0 mm point, OPEN the BYPASS valve, then press [ENTER]. After a 5 second delay for stabilization, PG7000 begins the fall rate measurement. The display is:
1. Indication of tare piston position.
2. Indication of reference piston position.
3. 30 second count down.
4. Average “equilibrium fall rate” since start of the countdown.
T +0.1 mm R +0 .0
12.2 Xflo at ing 30
43
2
PG7000 is measuring the drop rate of the two pistons and calculating the “equilibrium fall rate”. Be sure to not interfere with the free movement of the piston-cylinders or to introduce any outside interference while the countdown occurs. The fall rate measurement continues until either piston has moved 1 mm or 30 seconds have elapsed. The measurement can also be concluded by pressing [ENTER]. When the fall rate measurement has concluded, the results are displayed:
1. Average “equilibrium fall rate” measured in last crossfloat.
2. Suggested mass change (in grams) on the tare (T) piston to achieve equilibrium based on equilibrium fall rate just measured.
∆-10.3 +0.050 g on T
Repeat 1yes 2no
2
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PG7000™ OPERATION AND MAINTENANCE MANUAL
Evaluate the quality of the equilibrium. Check the value of the “equilibrium fall rate”. Consider that the closer the rate is to zero, the better the equilibrium; consider that the suggested mass change on the tare piston times the mass to pressure conversion coefficient of the piston approximates the pressure value of the defect in the equilibrium. Check the difference between the DUT output with the BYPASS open and BYPASS closed to evaluate the zero error due to the equilibrium.
Select <1yes> to return to the crossfloat <B/P open, [ENT]> screen. If you are satisfied with the quality of the equilibrium, select <2no> to go to the
run screen in high line differential pressure mode and set differential pressures at this line pressure (see Section 3.9.4.2, Setting Differential Pressures at a High Line Pressure).
The value of the average “equilibrium fall rate” measured by the crossfloat
should typically be inside of ± 5 mm/min and/or the suggested mass adjustment should be inside of 50 mg.
The device under test (DUT) can often be used to evaluate the quality of the
equilibrium between the two pistons and to correct for the zero error caused by the defect in equilibrium. Observe the change in the DUT output when the system BYPASS valve is opened and closed with the pistons floating. With the system BYPASS valve open, by definition, the differential pressure applied to the DUT is zero. The change in the DUT output observed when the BYPASS valve is closed with the pistons floating is the zero error due to the defect in the crossfloat equilibrium. Consider correcting all of the DUT readings by the value of this offset to correct for the crossfloat zero error. When using the offset, keep in mind that, due to differential evolution of the two PG7000 piston-cylinder temperatures, the differential pressure at zero differential mass load may not be zero.
Setting Differential Pressures at a High Line Pressure
To meet the full performance potential of PG7000 high line differential mode
operation, external influences on the piston gauges must be reduced or eliminated. Air currents and vibrations are the most significant possible influences. Do not operate near an active air conditioning or heating duct, avoid opening and closing doors or any movement of personnel around the system.
It is not possible to operate in differential mode with leaks at any point in
the test system. Thoroughly leak check the system before operation and correct any leaks detected.
High line differential mode is often used to calibrate DUTs whose differential
pressure range is very low relative to the line pressure. These DUTs can easily be overpressured by inadvertently applying excessive pressure to one port. When operating in high line differential pressure mode, OPEN the system BYPASS valve to zero the differential across the DUT when there is any risk of overpressure.
© 1998-2002 DH Instruments, Inc. Page 70
3. GENERAL OPERATION
Before operating in differential mode the line pressure must be set (see Section
3.9.4.2, Setting a Line Pressure ([MODE], <3HLdif>, <1run>, <2yes>)). Once the line pressure is set, from a practical standpoint, operating in high line
differential mode is very similar to operating in gauge mode (see Section 3.9.11). All operator interaction is with the PG Terminal of the reference PG7102 or
PG7202. The PG Terminal of the tare PG7000 is for display only. The tare PG7000 PG Terminal keypad is locked out during high line differential mode operation.
Operation is in either pressure to mass or mass to pressure mode (see Section 3.9.12).
To operate in differential mode the system BYPASS valve must be closed (see Figure 10).
All mass loading and unloading to define differential pressures is made on the reference PG7000. Mass loading and unloading instructions follow conventional PG7000 mass loading protocol (see Section 3.6) but the differential mass loading instructions are “on top of” the line pressure mass load. The mass load corresponding to the line pressure on the tare and reference PG7000s must remain exactly the same throughout the differential measurements.
While in high line differential mode, the piston position and piston rotation Ready/Not Ready indicators on the reference PG7000 reflect the status of both the tare and the reference PG7000s. For the indicator to indicate Ready, both the tare and the reference PG7000s must meet their current Ready/Not Ready criteria (see Section 3.4). A <T> in a Ready/Not Ready status indicator indicates that the tare PG7000 is Not Ready.
When operating in high line differential mode, the measurement mode
indicating character directly to the right of the pressure unit of measure in the main run screen is <d> (see Section 37).
Zero differential pressure (BYPASS valve closed) can be set by the system.
In some cases, the differential mass to load to set zero is not zero. This is normal and can occur due to differential changes in the temperature of the tare and reference piston-cylinders after the original line pressure crossfloat. A differential piston-cylinder module temperature change while running in high line differential mode affects the line pressure causing an offset to the differential pressure. The offset to the differential pressure causes a non-zero differential mass load to be needed to set zero differential pressure (see Section 7.2.1). Conversely, and for the same reason, a differential mass load of zero may not result in a differential pressure of zero.
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PG7000™ OPERATION AND MAINTENANCE MANUAL
Typical Sequence to Set Differential Pressures at a High Line Pressure Set the desired line pressure (see Section 3.9.4.2, Setting a Line
Pressure ([MODE], <3HLdif>, <1run>, <2yes>)).
Select pressure to mass or mass to pressure mode (see Section 3.9.12). If desired, read DUT output at zero differential pressure with BYPASS valve
OPEN. Then, put the BYPASS valve in CLOSED position. Float both PG7000 pistons before operating the BYPASS valve. Read DUT output at zero as defined by the PG7000s if desired (this value can be used as an offset correction on subsequent DUT differential pressure outputs).
Press [ENTER] and enter a pressure or mass value. All mass loading and
unloading to define differential pressures is performed on the reference PG7102 or PG7202. Follow normal PG7000 mass loading protocol (see Section 3.6). Note, however, that the mass loading instructions are “on top of” the mass already loaded to define the line pressure. The mass corresponding to the line pressure must remain exactly the same on both the tare and reference PG7000s throughout the differential pressure measurements.
Float the tare and reference pistons. For best results put both pistons
slightly above the 0.0 point, for example +0.3 mm.
When the reference PG7102 or PG7202 indicates Ready on both
Ready/Not Ready indicators (see Section 3.4), take the DUT reading at
the differential pressure indicated on the top line of the reference display. For best results log DUT readings and average them over time while the PG7000 pistons fall through the 0.0 mm point. Averaging for 10 to 30 seconds allows the random pressure noise from piston rotation to be integrated and eliminated.
Repeat Steps  through for each desired differential pressure point. If the last differential pressure is zero, consider reading the DUT output with
the BYPASS valve CLOSED. Then OPEN the BYPASS valve to set “true” zero differential pressure.
Viewing Line Pressure, Starting Piston-Cylinder Temperatures and Natural Piston Fall Rates ([MODE], <3HLdif>, <2view>)
To view the last line pressure setting, the starting piston-cylinder module temperatures, the natural piston fall rates and the “natural fall rate difference” recorded at that line pressure, press [MODE] and select <3HLdif>, <2view>. The display is:
1. Last line pressure value set (line pressure is always in gauge mode).
2. Temperature of the reference piston-cylinder logged when the line pressure crossfloat was completed.
3. Temperature of the tare piston-cylinder module logged when the line pressure crossfloat was completed.The starting temperatures are the temperatures logged at the time the line pressure setting crossfloat was completed. These
temperatures are used in calculating corrections to the differential pressure to take into account
differential temperature changes in the piston after completion of the crossfloat (see Section
7.2.1 for differential pressure calculation information).
Line P: 1000 psi T 21.24 °C R 21.47
3
2
© 1998-2002 DH Instruments, Inc. Page 72
3. GENERAL OPERATION
Press [ENTER] to continue to the next view screen or [ESCAPE] to go to the previous screen. The next view screen is:
1. Average fall rate of the tare piston recorded at the last line pressure.
2. Average fall rate of the reference piston recorded at the last line pressure.
3. Difference between the reference and tare piston average fall rates (R - T). This is the “natural fall rate difference”.
T-0.91 mm/min R-1.10
-0.2 Save 1yes 2no
3
2
The “natural fall rate difference” is the difference between the fall rates of
the two pistons when they are floating naturally at the line pressure. The “natural fall rate” can change slightly as operating conditions change so the “natural fall rate” determination and piston crossfloat procedure should be performed at the beginning of each sequence of differential pressure definitions.
To return to the <HLDif mode:> menu, press [ESCAPE]. To return to the previous run screen, press [ENTER].
3.9.5 [SYSTEM]
PURPOSE
To access the two SYSTEM run screens which display current values of PG7000 piston behavior, piston-cylinder temperature and vacuum reference (PG7601 only) measurements.
OPERATION
To access the SYSTEM run screens, press [SYSTEM] from any other run screen. There are two SYSTEM run screens. Pressing [SYSTEM] or [±] when in a SYSTEM screen toggles between the first and second SYSTEM screen.
See Sections 3.9.5.1 and 3.9.5.2 for detailed information on operation of the first and second SYSTEM run screens.
The SYSTEM screens are run screens. This means that other functions can be accessed
from the SYSTEM screens and the active SYSTEM screen will be returned to when leaving functions. The MAIN screen and AMBIENT screen are also run screens (see Section 3.8).
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PG7000™ OPERATION AND MAINTENANCE MANUAL
3.9.5.1 FIRST SYSTEM RUN SCREEN
OPERATION
The first SYSTEM run screen provides real time display of piston rotation rate and decay in piston rotation rate, piston position and piston fall rate.
To access the first SYSTEM run screen, press [SYSTEM] from any other run screen.
The first SYSTEM run screen displays:
1. <nnn rpm>: Numerical value of current piston rate of rotation. The unit of measure is rotations per minute [rpm] and cannot be changed. Flashes when Not Ready and piston is floating (see Section
3.4.2). Indicates < ---- > when information is unavailable or out of range.
2. <±nn/min>: Numerical value of current piston decay in rotation rate (deceleration). The unit of measure is rotations per minute per minute [rpm/min] and cannot be changed. < ---- > when information is unavailable or out of range.
3. <±n.nn/min>: Sign and numerical value of current piston movement. A negative value indicates piston falling. A positive value indicates piston rising. The unit of measure is millimeters per minute [mm/min] and cannot be changed. Indicates < ---- > when information is unavailable or out of range.
4. <±n.nn mm>: Sign and numerical value of current position of the piston within the piston stroke (see Section 3.5). The unit of measure is millimeters [mm] away from mid-stroke position and cannot be changed. Indicates <HSTOP> when the piston is at the high stop (all the way up) and <LSTOP> when the piston is at the low stop (all the way down). Flashes when Not Ready and piston is floating (see Section 3.4.1). Indi ca te s < ---- > when information is unavailable or out of range.
2
nnn rpm ±nn/min ±±n.nn mm n.nn/min
4
3
Pressing [ESCAPE] in the first SYSTEM run screen returns operation to the MAIN run screen. Pressing [SYSTEM] or [±] toggles between the first and second run screen. All function keys are active from the first SYSTEM run screen and operation returns to that screen when leaving functions the were accessed from it.
The measurement systems for piston behavior indications rely on movement
of the mass loading bell. Piston behavior indications (piston position, piston rotation rate) are not valid when the mass bell is not loaded on the piston.
See Section 3.5 for information on the piston stroke and measurement
zone.
© 1998-2002 DH Instruments, Inc. Page 74
3. GENERAL OPERATION
3.9.5.2 SECOND SYSTEM RUN SCREEN
OPERATION
The second SYSTEM run screen displays the values of piston-cylinder temperature and temperature rate of change currently used by PG7000. PG7601 also displays reference vacuum and vacuum rate of change. If internal measurement is specified for these values in SETUP (see Section 3.10), the second SYSTEM run screen provides a real time display of the values measured.
To access the second SYSTEM run screen, press [SYSTEM] or [±] from the first SYSTEM run screen. To access the first SYSTEM run screen, press [SYSTEM] from any run screen.
The second SYSTEM run screen displays:
1. <n.nn°C>: Current piston-cylinder temperature. Source of value can be internal measurement, default or user depending on current SETUP selection (see Section 3.10). The unit of measure is degrees Centigrade [±°C] and cannot be changed. Indicates < ---- > when information is unavailable or out of range.
2. <+n.nn/min>: Sign and numerical value of current rate of change of temperature. A negative value indicates temperature decreasing. A positive value indicates temperature increasing. The unit of
measure is degrees Centigrade per minute [°C/min] and cannot be changed. Indicates < ---- >
when information is unavailable or out of range. Indicates < ---- > when “user” or “default” is the current SETUP selection for piston-cylinder temperature source (see Section 3.10).
3. <+nnn.n/min>: Sign and numerical value of current rate of change of the vacuum reference pressure. A negative value indicates pressure decreasing. A positive value indicates pressure increasing. The unit of easure is Pascal per minute [Pa/min] and cannot be changed. Indicates < ---- > when information is unavailable or out of range. <Blank> if the PG7000 model is not PG7601 or if user or default is the current SETUP selection for reference vacuum (see Section 3.10).
4. <nnn.n Pa>: (Used for PG7601 only.) Current vacuum reference value. Can be internal measurement, default or user depending on current SETUP selection. Flashes when Not Ready and piston is floating (see Section 3.4.3). The unit of measure is Pascal [Pa] and cannot be changed. Indicates < >20 Pa > if current SETUP selection is internal and current measurement is out of range or greater than 20 Pascal. <Blank> if PG7000 model is not PG7601.
n.nn
°±n.nn/min
C
nnn.n Pa nnn.n/min±
4
2
3
Pressing [ESCAPE] in the second SYSTEM run screen returns operation to the MAIN run screen. Pressing [SYSTEM] or [±] toggles between the first and second SYSTEM run screen. All function keys are active from the second SYSTEM run screen and operation returns to that screen when leaving functions that were accessed from it.
The current selection in SETUP determines the source of the values used by
Page 75 © 1998-2002 DH Instruments, Inc.
PG7000 for piston-cylinder temperature and vacuum reference values. If the SETUP setting is user or default, the SYSTEM screen displays the user or default value, not PG7000’s on-board measurement(s).
PG7000™ OPERATION AND MAINTENANCE MANUAL
3.9.6 [AMBIENT]
PURPOSE
Access the AMBIENT run screen which displays the current ambient condition values being used by PG7000 for calculations of reference pressures.
PRINCIPLE
PG7000 uses ambient condition values to calculate the reference pressures that it defines (see Section 0). The source of the ambient condition values is specified in the current SETUP file (see Section 3.10). The AMBIENT run screen displays the current ambient condition values. If the SETUP selection for the ambient condition is internal measurement, then the AMBIENT run screen provides a real time display of the measurement of PG7000’s on-board sensor for that variable.
OPERATION
To access the AMBIENT run screen, press [AMBIENT] from any other run screen (MAIN or SYSTEM).
The AMBIENT screen is a run screen. This means that other functions can be accessed from
the AMBIENT screen and the active AMBIENT screen will be returned to when leaving functions. The MAIN screen and SYSTEM screens are also run screens (see Sections 3.7 and
3.9.5).
The AMBIENT run screen displays:
1. <nnnnnnn uuuu>: Current numerical value and pressure unit of atmospheric pressure. Source of value can be internal measurement, remote barometer, default or user depending on current SETUP selection (see Section 3.10). The unit of measure is determined by the UNIT function setting (see Section 3.9.3). ATM head is applied to internal or external barometer reading to correct atmospheric pressure to the PG7000 reference level (see Section 3.11.3.3). Indicates < ---- > when information is unavailable or out of range. Indicates <TIMEOUT> if the current SETUP selection is a remote barometer and PG7000 communication with the barometer times out.
2. <n.nn°C>: Current ambient temperature. Source of value can be internal measurement, default or user depending on current SETUP selection (see Section 3.10). The unit of measure is degrees Centigrade [ºC] and cannot be changed. Indicates < ---- > when information is unavailable or out of range.
3. <n.nnnnnnm/s2>: Value of local acceleration due to gravity. Can be default or user depending on current SETUP selection (see Section 3.10). The unit of measure is meters per second squared (m/s2) and cannot be changed.
4. <nn%RH>: Current ambient relative humidity. Can be internal measurement, default or user depending on current SETUP selection (see Section 3.10). The unit of measure is percent relative humidity (%RH) and cannot be changed. Indicates < -- > if current SETUP selection is internal and current measurement is unavailable or out of range.
nnnnnnn uuuu nn.n C
nn%RH n.nnnnnn/s2
2
°
34
Pressing [ESCAPE] in the AMBIENT run screen returns operation to the MAIN run screen. All function keys are active from the AMBIENT run screen and operation returns to that screen when leaving functions that were accessed from it.
The current selection in SETUP determines the source of the values used by PG7000 for
atmospheric pressure, ambient temperature and relative humidity. If the SETUP setting for these values is user or default, the AMBIENT screen displays the user or default value, not PG7000’s on-board measurement(s).
To change the ambient pressure units of measure, see Section 3.9.3. When the current
pressure unit of measure is an altitude unit, atmospheric pressure in the AMBIENT run screen is expressed in kPa if the altitude unit is meters (m) or psi if the altitude unit is
© 1998-2002 DH Instruments, Inc. Page 76
3. GENERAL OPERATION
feet (ft).
3.9.7 [HEAD]
PURPOSE
To cause a pressure value, representing the fluid head resulting from a difference in height, to be added to the pressure defined by PG7000 at its reference level. To set the height of the DUT head.
PRINCIPLE
The pressure defined by the PG7000’s floating piston is the pressure at the bottom of the piston. This is referred to as the PG7000 reference level. The height of the bottom of the piston with the piston in mid-stroke position is marked reference level on the PG7000 piston-cylinder module mounting post. Frequently, when performing a calibration or test, the device or system under test is at a different height than the PG7000 reference level. This difference in height (referred to as DUT head) can cause a significant difference between the pressure defined by the PG7000 at its reference level and the pressure actually applied to the device under test located at a different height. In this case, it is useful to make a head correction to the pressure defined by the PG7000 at its reference level in order to accurately predict the pressure actually applied at a different height. The HEAD function allows this head corr e ction to be applied automatically for a variety of fluids based on operator entry of the height difference. The fluid used and the HEAD function units of measure are set by pressing [SPECIAL] and selecting <3head> (see Section 3.11.3).
PG7000 can accurately determine head pressures for gases (nitrogen, helium and air) and liquids (Di-2 ethylhexyl Sebacate oil, water and a user defined liquid) as the pressurized medium.
When gas is the test fluid, use of the HEAD function is most important at low
absolute pressures. In this case, specifying the head height within ± 0.2 in. (5 mm) is adequate to ensure that, even in the worst case, the uncertainty on the head correction will be insignificant relative to the tolerance on the PG7000 measurement. Use of the HEAD function to ensure tolerance measurements is particularly critical when a liquid is the test fluid, due to the high density of liquids. To determine when and how precisely a head correction for liquids must be made, 0.03 psi/inch (90 Pa/cm) may be used as an estimation of the liquid head value.
Regardless of the head function’s setting, corrections are automatically applied to the
calculated reference pressure to compensate for the deviation between the current piston position and the mid-stroke position (see Section 3.11.3.4).
The pistons of certain gas operated piston-cylinder modules are hollow. Due to their
irregular shape, for these pistons, the natural reference level is not at the bottom of the piston. So that, in practice, the actual reference level is the same for all piston-cylinder modules, a reference level offset is applied when a hollow piston is used. The reference level offset is included in the piston-cylinder file (see Section 3.11.1.1) and corrects the reference level back to the reference point marked on the mounting post.
Page 77 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
OPERATION
To access the HEAD function, press [HEAD]. The display is:
1. Test fluid currently specified for the head correction.
2. Entry field for head height (1 to 999 cm or in.).
95 cm N2
Entering a value of zero turns the HEAD function OFF. Entering a value other than zero turns the HEAD function ON using the height entered. Pressing [ESCAPE] returns to the main run screen with NO change to the current head setting.
Edit DUT head height:
(+)
Reference
Line
REFERENCE LEVEL
(-)
The reference height of PG7000 pressure definition is the bottom of the piston in mid-
stroke float position. This position is marked on the piston-cylinder module mounting
+
post. The DUT head height should be entered as a positive value if the device or system under test is higher than the PG7000 reference level and negative if it is lower.
To change units of DUT head height between inches and centimeters and to change the
test fluid, press [SPECIAL] and select <3Head> (see Section 3.11.3).
When the HEAD function is ON (DUT head value different from 0), the application of a head
correction is indicated by <h> in the right side of the top line of the MAIN run screen (see Section 3.7). When the HEAD function is OFF, the <h> is NOT shown. PG7000’s also have a separate head correction to compensate for the deviation between the current piston position and mid-stroke (see Section 3.11.3.4). This PISTON head can be turned ON and OFF (see Section 3.11.3.4).
© 1998-2002 DH Instruments, Inc. Page 78
3. GENERAL OPERATION
3.9.8 [ROTATE] (OPTIONAL ON PG7102, PG7202 AND PG7302)
PURPOSE
See Section 3.9.13 for information on manual control of motorized piston rotation.
PRINCIPLE
PG7000s offer a motorized piston rotation system. Motorized rotation is standard on PG7601 and optional on PG7102, PG7202 and PG7302.
The motorized piston rotation system operates by engaging a motor driven belt system around the bottom of the mass loading bell which accelerates the rotation rate of the mass bell and piston it is loaded on. The motorized rotation system can engage with the piston at any position in its stroke and at any rotation speed with minimal impact on piston position and the defined pressure. When the motorized rotation system disengages, the piston is left to rotate freely of its own momentum.
With automatic motorized rotation ON, the motorized rotation system engages and disengages automatically as needed when the piston is floating to maintain the piston rotation rate within Ready condition rotation rate limits (see Section 3.4.2). The rotation rate is measured by PG7000 on board sensors and the rotation rate limits are set by the current SETUP file (see Section 3.10). Whenever the piston is floating, the motorized rotation system will attempt to maintain the piston rotation rate within the Ready limits (except under the cutoff mass load of 2.5 kg for PG7601 and 3 kg for PG7102 and PG7302 where the low rotation limit becomes 5 and 2 rpm, respectively). The piston rotation Ready/Not Ready indication character indicates Not Ready to alert the operator when the motorized rotation system is about to engage. The rotation system will not engage when the current mass load is less than the mass of the piston + mass loading bell.
To turn automatic control of motorized piston rotation ON and OFF.
With automatic motorized rotation OFF, the motorized rotation system engages only when actuated by the operator. The operator can actuate motorized rotation by pressing [
] (see
Section 3.9.13). Automatic motorized rotation is generally left ON for normal operation. It is turned OFF in
situations where rotation system actuation independent of operator initiative is undesired (e.g., when performing a crossfloat intercomparison with another piston gauge).
OPERATION
If PG7000 is equipped with motorized rotation, pressing [ROTATE] from any run screen changes the ON/OFF state of automatic motorized rotation control.
If PG7000 is NOT equipped with motorized rotation, <Automatic rotation not available> is displayed momentarily when [ROTATE] is pressed.
If PG7000 is equipped with motorized rotation and automatic motorized control is ON, when [ROTATE] is pressed <Turning OFF automatic rotation> is displayed momentarily and automated rotation is turned OFF. The PG7000 motorized rotation system will only engage if the operator presses [
] (see Section 3.9.13).
If PG7000 is equipped with motorized rotation and automatic motorized rotation is OFF, when [ROTATE] is pressed <Turning ON automatic rotation> is displayed momentarily and automated rotation is turned ON. The PG7000 motorized rotation system will engage automatically to maintain the rotation rate within the rotation rate ready limits (see Section
3.4.2) any time the piston is floating. Manual control using [
] is also still active.
Page 79 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
Automatic motorized piston rotation is dependent on PG7000’s measurements of
piston position and rotation rate. These measurements are only available when the mass loading bell is installed on the piston. Automatic piston rotation is suspended when the current PG7000 mass load does not include the mass loading bell.
When PG7601 is operating in absolute by vacuum mode using the internal vacuum sensor
to measure reference vacuum, automatic motorized piston rotation will not engage until the reference vacuum value is within the Ready limit (see Section 3.4.3).
The motorized rotation system is protected against overloading. If the duty cycle
become excessive, motorized rotation cuts OFF and remains off for a 25 second delay. During the cutoff time [
] has no effect.
3.9.9 [GEN] (OPTIONAL)
PURPOSE
To turn ON and OFF automated pressure generation/control. Requires that an automated pressure generation/control component be included and properly configured in the PG7000 system.
PRINCIPLE
PG7000s support certain automated pressure generation/control components. These components, when properly configured and interfaced with PG7000, are controlled by PG7000 to automatically set and adjust pressure to float the PG7000 piston. Automated pressure generation and control components are interfaced via PG7000’s COM3 RS232 port (see Section 3.11.5.1).
Once an automated pressure generation/control component has been properly configured and interfaced with PG7000, pressing [GEN] will turn the automated pressure generation/control ON and OFF.
With automated pressure generation/control ON, PG7000 will send commands to the automated pressure generation/control component once mass loading has been confirmed after any mass to pressure or pressure to mass command (see Section 3.9.11). It will continue to attempt to float its piston until [ENTER] is pressed to initiate a new command or automated pressure generation/control is turned OFF by pressing [GEN].
With automated pressure generation/control OFF, PG7000 will leave the automated pressure generation/control component idle and will not attempt to float its piston.
If an automated pressure generation/control component is included in the PG7000 system, automated pressure generation/control is generally left ON for normal operation. It is turned OFF in situations where pressure control independentl of operator initiative is undesired (e.g., when performing a crossfloat intercomparison with another piston gauge).
OPERATION Pressing [GEN] from any run screen changes the ON/OFF state of the PG7000 automated
pressure generation/control function. If automated pressure generation/control is OFF, PG7000 attempts to turn automated
pressure generation/control ON when [GEN] is pressed. To do so, it must be able to establish communication over its COM3 RS232 port (see Section 3.11.5.1) with a valid pressure generation/control component. If PG7000 is unable to establish communication with a valid pressure generation/control component, <P control timeout, autogen off>
© 1998-2002 DH Instruments, Inc. Page 80
3. GENERAL OPERATION
is displayed momentarily. Correct the communications error with the pressure generation/control component and try again.
If automated pressure generation/control is OFF, when [GEN] is pressed and PG7000 is able to establish communications with a valid automated pressure generation/control component, <Turning ON automated generation> is displayed momentarily and automated generation/control is turned ON. The operator is then queried to set the <Piston float zone> which is the band around piston midfloat position within which PG7000 will attempt to float its piston (see Section 3.5). The PG7000 automated generation/control function will attempt to float the piston within the piston position ready limits (see Section 3.4.1) once mass loading has been confirmed after any mass to pressure or pressure to mass command. It will continue to attempt to float its piston until [ENTER] is pressed to initiate a new command/or automated pressure generation/control is turned OFF using [GEN].
If automated pressure generation/control is ON when [ROTATE] is pressed, <Turning OFF automated generation> is displayed momentarily and automated generation/control is turned OFF. The PG7000 automated generation control function is inactive.
Proper operation of the automated pressure generation/control function is dependent on
PG7000’s measurements of piston position and rotation rate. These measurements are only available when the mass loading bell is installed on the piston. Automated pressure generation/control is automatically turned off when the PG7000 entered pressure or mass load does not include the mass loading bell.
Automated pressure generation is not available when operating in PG7000 high line
differential pressure mode (see Section 3.9.4.2).
3.9.10 [RES]
PURPOSE
To set the resolution of PG7000 mass loading commands (see Section 3.9.12).
PRINCIPLE
PG7000 piston-cylinders are sized such that there is a whole number, nominal relationship between mass loaded on the piston in kilograms [kg] and the pressure at which the piston will float in kilo Pascal [kPa] or Mega Pascal [MPa]. This relationship is called the mass to
pressure conversion coefficient and is expressed as kPa/kg or MPa/kg. The pressure to mass conversion coefficient is marked on the cap of each piston.
PG7000 mass sets are made up of masses in multiples and submultiples of the kilogram making it simple to load mass values rounded to 0.01 g, 1 g, 10 g or 0.1 kg.
When using PG7000 to define pressures, the desired pressure value is entered (see Section
3.9.11) and PG7000 prompts the user with the mass value to be loaded. Due to the many variables that influence the exact pressure to mass relationship for a piston-cylinder (even though there is nominally a whole number mass to pressure) the mass value to load to reach exactly the pressure requested is always an odd value. Therefore, defining the exact pressure value requested always requires loading mass with 0.01 g resolution.
When it is acceptable for the pressure values defined to not be exactly the nominal pressure value of the point, operation can be simplified and mass loading errors can be reduced by loading mass with a lower level of resolution and using the pressure that the lower level resolution mass load generates. For example, on a piston-cylinder with a nominal pressure to mass relationship of 10 kPa/kg, defining a pressure of exactly 100 kPa, nominally requires loading 10 kg of mass. However, once all the influences on the measurement are taken into consideration, the actual mass to load to define exactly 100 kPa will not be 10.00000 kg, it
Page 81 © 1998-2002 DH Instruments, Inc.
PG7000™ OPERATION AND MAINTENANCE MANUAL
will be a value near 10 kg such as 9.99731 kg. This value is difficult to load as it requires relatively complex mass accounting and the manipulation of very small sub-gram masses. To avoid handling a difficult odd mass value, one might instead decide to load 10 kg and use whatever pressure results as the reference pressure. In this example, loading 10 kg rather than 9.99731 kg would result in defining 100.0269 kPa rather than 100.0000 kPa. The pressure defined is only very slightly different from the nominal value and there is no additional uncertainty if that value is used. The savings in time and reduction of possible mass loading errors are significant.
The PG7000 RES function is used to cause PG7000 to automatically calculate mass loads to a whole number value starting at 0.01 g and increasing in powers of 10 to 0.1 kg. This function is very useful to make operation more convenient and less error prone when it is not imperative that the pressure defined by PG7000 be exactly the nominal pressure of the test of calibration sequence.
OPERATION
To access the resolution function, press [RES]. The display is:
Mass loading rsltn:
0.01 g < and >
Press the [] and [] keys to select the desired level of resolution. [] decreases resolution and [] increases resolution. Press [ENTER] to set the selected resolution and return to the main run screen. There resolution range is from 0.01 g to 0.1 kg in powers of
10.
The RES setting has no affect in mass to pressure mode. The RES setting only affects
the resolution of the mass commands that result from pressure entries in pressure to mass mode (see Section 3.9.12).
In PG7000 high line differential pressure mode (see Section 3.9.4.2), line pressures
setting is not affected by the RES setting; line pressures are always set with
0.1 kg resolution. Differential pressure mass loading resolution is determined by the RES setting.
3.9.11 [ENTER] FROM RUN SCREEN
PURPOSE
To enter and execute pressure to mass or mass to pressure commands (see Section 3.9.12).
PRINCIPLE
PG7000 can calculate and display the mass to be loaded to achieve an entered pressure value (pressure to mass mode), or the pressure resulting from an entered mass load (mass to pressure mode). The P mode (see Section 3.9.12).
Pressing [ENTER] from any run screen (MAIN, SYSTEM or AMBIENT) accesses the pressure or mass entry screen which allows the command value to be entered and proceeds through the sequence to set or read the pressure defined by PG7000.
© 1998-2002 DH Instruments, Inc. Page 82
OR M function is used to set pressure to mass or mass to pressure
3. GENERAL OPERATION
OPERATION
To access the pressure or mass entry screen, press [ENTER] from any run screen. The sequence after [ENTER] has been pressed varies between mass to pressure and pressure to
mass mode. Th e mode is selected by pressing [P
OR M] (see Section 3.9.12). See Section
3.9.11.1 for details on pressure to mass mode and Section 3.9.11.2 for mass to pressure mode. See immediately below for typical operational sequences in gauge and absolute modes. See Section 3.9.4.1, Operating in Differential Mode
, for typical differential mode operational
sequence.
Typical Gauge and Absolute by ATM Mode Operational Sequence
Press [MODE] and select gauge or absolute by ATM mode as desired (see Section 3.9.4). Press [P
OR M] and select pressure to mass or mass to pressure mode (see Section 3.9.12).
Press [ENTER] and enter a pressure or mass value. Load mass as instructed (see Section 3.6). Use system control component to float the PG7000 piston. When PG7000 indicates Ready on all Ready/Not Ready indicators (see Section 3.4), take a
DUT reading at pressure indicated on the top line of PG7000 display.
Repeat Steps through for each desired differential pressure point.
Typical Absolute by Vacuum Mode Operational Sequence (PG7601 Only)
Press [MODE] and select gauge or absolute by ATM mode as desired (see Section 3.9.4). Press [P
OR M] and select pressure to mass or mass to pressure mode (see Section 3.9.12).
Press [ENTER] and enter a pressure or mass value. Load mass as instructed (see Section 3.6). Install bell jar on PG7000, shut PG7000 vacuum vent valve, open vacuum reference
shutoff valve. Wait for vacuum under bell jar to reach Ready condition (see Section 3.4.3).
Use system control component to float the PG7000 piston. When PG7000 indicates Ready on all Ready/Not Ready indicators (see Section 3.4), take a
DUT reading at absolute pressure indicated on the top line of the PG7000 display.
Shut vacuum reference shutoff valve, open vacuum vent valve. Wait for pressure under
bell jar to return to ambient. Remove bell jar.
Repeat Steps  through for each desired differential pressure point.
3.9.11.1 [ENTER] IN PRESSURE TO MASS MODE
PURPOSE
To enter and execute a pressure to mass command in pressure to mass mode (see Section 3.9.12).
OPERATION
Put the PG7000 in pressure to mass operation mode (see Section 3.9.12), then press [ENTER] in any run screen.
Pressing [ENTER] in the run screen causes automated pressure generation
Page 83 © 1998-2002 DH Instruments, Inc.
and/or motorized piston rotation to suspend if ON (see Section 3.9.9) so that masses can be loaded and unloaded without interference. When [ENTER] is pressed to confirm mass entry, automated pressure generation and/or motorized rotation resume.
PG7000™ OPERATION AND MAINTENANCE MANUAL
The display is:
1. Current measurement mode (see Section 3.9.4).
2. Current pressure unit of measure (see Section 3.9.3).
3. Entry field for the target value of pressure to be set.
Target pressure:
100.0000 kPa a
3
2
Use the numerical keys and editing keys to enter the target pressure value desired. Press [ENTER] to process the target pressure value. If the pressure value
entered cannot be processed, an explanatory error message is displayed momentarily and operation returns to the target pressure entry screen with the previous target pressure value displayed. If the target pressure value entered is valid, the value is processed and operation proceeds to the mass loading instruction screen. The display is:
1. Mass to load using trim masses.
2. Nominal mass to load using main and fractional masses.
Load nominal mass:
10.0 kg and 3.17 g
2
With PG7601 in absolute by vacuum measurement mode (see Section 3.9.4), the instruction is <Load mass & vac:> indicating that the nominal mass value should be loaded and then the bell jar should be installed and vacuum established under the bell jar.
Load the nominal mass value following the protocol described in Section 3.6 and press [ENTER]. When [ENTER] is pressed confirming that the nominal mass value has been loaded, operation returns to the previous run screen with the new pressure target and mass value active.
To make “in tolerance” measurements, it is imperative that all mass loading
instructions be executed following the protocol describe in Section 3.6. This ensures that the actual mass value resulting from a nominal mass loading command will be correct. Failure to load masses following the PG7000 mass loading protocol is likely to result in out of tolerance mass load determinations and pressure definitions.
The resolution with which the pressure to mass mode mass loading
instruction is given depends on the resolution set in the RES function. The RES function makes it possible to avoid loading high resolution mass values when it is not imperative that the pressure defined be exactly the nominal pressure requested (see Section 3.9.10).
The pressure to mass loading instruction is given in nominal mass while the
main run screen displays the true mass loaded. For this reason, the nominal mass loading instruction and the true mass displayed in the main run screen are slightly different values. This is normal operation (see Section 3.6).
© 1998-2002 DH Instruments, Inc. Page 84
3. GENERAL OPERATION
3.9.11.2 [ENT] IN MASS TO PRESSURE MODE
PURPOSE
To enter and execute a mass to pressure command in mass to pressure mode (see Section 3.9.12).
OPERATION
Put the PG7000 in mass to pressure operation mode (see Section 3.9.12), then press [ENTER] in any run screen.
Pressing [ENTER] in the run screen causes automated pressure generation
and/or motorized piston rotation to suspend if ON (see Section 3.9.9) so that masses can be loaded and unloaded without interference. When [ENTER] is pressed to confirm mass entry, automated pressure generation and/or motorized rotation resume.
The display is:
1. Edit field for total trim mass currently loaded.
2. Edit field for nominal mass of main and fractional masses currently loaded.
Load nominal mass:
10.0 kg and 3.17 g
2
Use the numerical keys and editing keys to enter the nominal mass currently loaded on the piston following the mass loading protocol described in Section
3.6. Press [ENTER] to process the mass value. If the mass value entered cannot be processed, an explanatory error message is displayed momentarily and operation returns to the mass entry screen with the previous nominal mass value displayed. If the mass value entered is valid, the value is processed and operation proceeds to the previous run screen with the new mass value active.
To make “in tolerance” measurements, it is imperative that the value of
mass loaded on the piston be the NOMINAL mass following the protocol describe in Section 3.6. This ensures that PG7000 will correctly determine the true mass value loaded. Failure to enter nominal mass values following the PG7000 mass loading protocol is likely to result in out of tolerance mass load determination and pressure definitions.
The setting of the RES function has no effect on the resolution of mass load
entries in mass to pressure mode (see Section 3.9.10).
The mass to pressure mass entry is expressed in nominal mass while the
Page 85 © 1998-2002 DH Instruments, Inc.
MAIN run screen displays the true mass loaded. For this reason, the nominal mass loading instruction and the true mass displayed in the main run screen are slightly different values. This is normal operation (see Section 3.6).
PG7000™ OPERATION AND MAINTENANCE MANUAL
3.9.12 [P OR M]
PURPOSE
PRINCIPLE
Piston gauges are generally used either to define desired pressure set points (e.g., when applying reference pressures to a device to be calibrated) or to measure a static pressure (e.g., when performing a crossfloat intercomparison with another piston gauge). PG7000s support these two typical situations with two operating modes: pressure to mass and mass to pressure.
In pressure to mass operating mode, the operator enters target pressure values and the PG7000 provides instructions of the mass to load to achieve the desired target pressure.
In mass to pressure operating mode, the operator enters the mass currently loaded and the PG7000 determines the pressure resulting from the current mass load. Mass to pressure mode is also useful to determine the true mass resulting from a nominal mass load (see Section 3.6).
To select between PG7000 pressure to mass or mass to pressure operation mode.
The P
OR M function is used to set the PG7000 operating mode to either pressure to mass or
mass to pressure.
OPERATION
For details on pressure to mass and mass to pressure operation, see Section 3.9.11.
To access the P OR M function, press [P OR M], the display is:
Select entry mode:
1pressure 2mass
Selecting <1pressure> activates pressure to mass mode and returns to the previous run screen. Selecting <2mass> activates mass to pressure mode and returns to the previous run screen.
3.9.13 [ ]
PURPOSE
To activate motorized piston rotation manually.
Motorized piston rotation is optional on PG7102, PG7202 and PG7302. If motorized
rotation is not present, pressing [ ] displays an informational message and has no effect.
PRINCIPLE
PG7000 offers motorized piston rotation as a standard feature on PG7601 and as an optional feature on PG7102, PG7202 and PG7302. Motorized rotation engages and disengages to rotate the PG7000 piston.
Motorized rotation can be set to operate automatically to maintain the piston within Ready condition rotation rate limits when the piston is floating (see Section 3.9.8). Motori zed rotation can also be engaged manually to drive the piston at any time under direct operator control.
] is used for momentary engagement of the motorized rotation system under direct
[
operator control.
© 1998-2002 DH Instruments, Inc. Page 86
3. GENERAL OPERATION
OPERATION
To momentarily engage the motorized piston rotation system, press [ run screen. If PG7000 is equipped with motorized rotation, the motorized rotation system engages and remains engaged until maximum rotation rate has been achieved or the key is released.
When [
] is pressed, the display goes to the first SYSTEM run screen (see Section 3.9.5.1)
to provide a real time indication of piston rotation rate. When [ returns to the previous run screen.
The motorized rotation system is protected against overloading. If the duty cycle
becomes excessive, motorized rotation cuts OFF and remains off for a 25 second delay. During the cutoff time, [
The motorized rotation system is set to operate automatically based on current piston
position and rotation rate. See Section 3.9.8 for information.
In PG7000 high line differential mode (see Section 3.9.4.2), pressing [ ] on the reference
PG7102 engages motorized rotation (if present) on both the reference and tare PG7000s.
3.10 [SETUP] MENU
] from any
] is released, the display
] has no effect.
PURPOSE
To select, view and edit the SETUP files that determine the source of the values that PG7000 uses in its calculation of defined pressure and as criteria for Ready/Not Ready condition determination.
PRINCIPLE
PG7000 piston gauges perform continuous, real time calculations of the pressure defined by the floating piston under current conditions (see Section 7.2 for the details on the calculations applied). The calculations are used to determine the defined pressure displayed in the MAIN run screen, and to arrive at the mass to load value when a target pressure is entered in pressure to mass mode.
The equations that PG7000 uses to calculate pressure include many instrument and ambient variables. PG7000 allows the source of the value used for each variable to be defined. For example, the value of barometric pressure used to calculate current air density and to add to gauge pressure to define absolute pressure in absolute by atmosphere mode could come either from PG7000’s internal sensor, an external barometer connected to PG7000’s COM2, a user entered value or be set to standard atmospheric pressure. The PG7000 SETUP function allows the source (and in some cases the value) of the variables used in the pressure equations to be specified. In order to allow various combinations of sources and/or values to be setup and recalled, SETUP files can be created, stored and recalled. The SETUP files also include certain variables used to determine PG7000 Ready/Not Ready status. Table 17 identifies the variables included in the SETUP file, the factory source setting for each variable and the default value for each variable.
Variable source and value selections are recorded in SETUP files. These files can be stored and recalled so that specific combinations of variable sources and/or values can be conveniently recalled. There are 20 SETUP files. File #1 is a factory SETUP file that cannot be edited. It includes the factory preferred variable choices and values.
SETUP files, USER values and PG7000’s calculation capabilities can be used to calculate defined
pressure in specific conditions independent of actual PG7000 operation.
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PG7000™ OPERATION AND MAINTENANCE MANUAL
The SETUP function supports the following:
View SETUP files (see Section 3.10.2);
Create/edit SETUP files (see Section 3.10.3);
Select active SETUP file (see Section 3.10.1.
Table 17. SETUP File Choices, Factory Preferred Choice and Normal Value
VARIABLE
Atmospheric pressure 1. Internal
Ambient temperature 1. Internal
Ambient relative humidity 1. Internal
Piston-cylinder temperature
Gravity 1. Local
Vacuum (PG7601 only)
Ready/Not Ready Piston position
Ready/Not Ready Maximum vacuum
reference pressure in absolute by vacuum mode (PG7601 only)
SOURCE
CHOICES
2. Normal
3. User
4. COM2
2. Normal
3. User
2. Normal
3. User
1. Internal
2. Normal
3. User
2. Normal
3. User
1. Internal
2. Normal
3. User
1. User 1. User
1. User 1. User 5 Pa (default)
FACTORY
PREFERRED CHOICE NORMAL VALUE
1. Internal 101.325 kPa (14.6959 psi)
1. Internal 20 °C
1. Internal 45 %RH
1. Internal 20 °C
1. Local 9.806650 m/s2
1. Internal 0 Pa
± 2.5 mm from midfloat position (default)
The factory preferred SETUP choice is the SETUP choice setting for all variables in a new SETUP file.
SETUP file #1 is set to factory SETUP choices and cannot be altered.
OPERATION
To access the SETUP menu, press [SETUP] from the main run screen. The display is:
#nn in the upper right hand corner displays the number of the SETUP file that is currently active. Select <1select> to select a different active SETUP file. Select <2view> to view the variable choices and
values of the active SETUP file. Select <3edit> to create or edit a SETUP file. See Sections 3.10.1 to 3.10.3 for detailed information on each SETUP function operation.
© 1998-2002 DH Instruments, Inc. Page 88
Current SETUP: #01
1select 2view 3edit
3. GENERAL OPERATION
3.10.1 <1SELECT>
PURPOSE
Changing the current SETUP file will change the source and in some cases the values of
the variables used by PG7000 in calculating defined pressure. SETUP files should be selected and changed only by qualified personnel. Incorrect SETUP file selection may cause out of tolerance calculations and measurements. See Section 3.10, PRINCIPLE, for information on SETUP files and their use.
OPERATION
To select a SETUP file number to make it the active SETUP file, press [SETUP] and select <1select>. In the following screen enter the number of the desired SETUP file and press [ENTER]. If a valid SETUP file number has been entered, operation returns to the previous
run screen with the selected SETUP file number displayed and active.
To change the active SETUP file number.
Entering an invalid SETUP file number causes an error message to be displayed briefly and
returns to the select SETUP file screen.
If the SETUP file selected specifies COM2 as the source of barometric pressure, PG7000
will attempt to read a barometer on COM2 when initializing the new SETUP file. If PG7000 is unable to read a barometer on COM2, a communications time out message is displayed briefly and operation returns to the select SETUP file screen. See Section
3.11.5.4 for information on configuring COM2 to read an external barometer.
3.10.2 <2VIEW>
PURPOSE
To view the variable source choices and values of any SETUP file number.
OPERATION
Selecting <2view> SETUP allows the variable source choices and values of the active SETUP
file for viewing only. <2view> does not make the viewed SETUP file active. To select the active SETUP file, press [SETUP] and select <1select>.
See Table 13 for a listing of the source choices for each variable.
To view an existing SETUP file, press [SETUP] and select <2view>. The display is:
View SETUP file:
1. Entry field for number of SETUP file to be viewed. Defaults to SETUP file currently selected. Must be a number from 2 to 10.
#02
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PG7000™ OPERATION AND MAINTENANCE MANUAL
Enter the desired SETUP file number and press [ENTER]. If a valid SETUP file number is entered, the display is:
View #02 latmP 2ambT
3%RH 4PCT 5g 6READY
7vac
Select <1atmP> to view the atmospheric pressure variable source choice and current value. The value is displayed in the current pressure units (see Section 3.9.3).
Select <2ambT> to view the ambient temperature variable source choice and the current value. The value is displayed in degrees Centigrade [°C].
Select <3%RH> to view the ambient relative humidity variable source choice and the current value. The value is displayed in %RH.
Select <4PCT> to view the piston-cylinder temperature variable source choice and the current value. The value is displayed in degrees Centigrade [°C].
Select <5g> to view the gravity variable source choice and the current value. The value is displayed in meters per second squared [m/s
2
].
Select <6READY> to view the values of Ready/Not Ready status criteria (see Section 3.4). These include:
<1Pposition>: Piston position Ready/Not Ready limits (see Section 3.4.1). The value is displayed as a band in millimeters about mid-float position [± mm] (see Section 3.5).
<2vac> (PG7601 only): Maximum reference vacuum pressure limit when operating in absolute by vacuum mode. The value is displayed in Pascal [Pa].
Select <7vac> (PG7601 only): to view the reference vacuum variable source choice and the current value. The value is displayed in Pascal [Pa].
3.10.3 <3EDIT>
PURPOSE
To edit an existing SETUP file and/or to create a new SETUP file.
See Section 3.10, PRINCIPLE for information on SETUP files and their purpose.
OPERATION
SETUP file #1 is the factory preferred file and it cannot be edited.
See Table 13 for a listing of the source choices for each variable.
To edit an existing SETUP file or create a new SETUP file, press [SETUP] and select <3edit>. The display is:
1. Entry field for number of SETUP file to be edited or created. Defaults to SETUP file currently selected. Must be a number from 2 to 10.
© 1998-2002 DH Instruments, Inc. Page 90
Edit SETUP file:
#02
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