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.
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.
1.2.3 MASS SETS...................................................................................................................................................8
2.1.1.2 MASS SET...............................................................................................................................................14
2.1.2.2 MASS SET...............................................................................................................................................19
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
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
3.11.1.5 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
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
3.11.5.3 RS232 SELF TEST ................................................................................................................................112
4.2.1.2 COM2 AND COM3.................................................................................................................................124
5.4 MASS SETS.........................................................................................................................................179
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!
T
T
HHIISS
M
AANNUUAAL
M
L
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]).
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
- 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.
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.
± 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.
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.
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.
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).
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
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
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.
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
: 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.
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.
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
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.
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.
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,
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.
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],
<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.
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).
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.
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).
]. 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.
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.
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.
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).
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)
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.
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
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).
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.
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.
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.
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.kgg.gg
Nominal mass load:
kg and gkkk.kgg.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.
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.
• 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
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).
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.
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).
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.
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.
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).
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).
*<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.
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.
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.
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:
= 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
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.
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
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.
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.
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
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.
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.
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.
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.
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
• 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 displayof 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.
While in high line differential pressure mode, the tare PG Terminal keypad
is inactive.
After high line differential mode is initialized, the displayof 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.
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.
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
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.
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.
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.
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).
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).
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
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
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
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.
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).
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 [
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>
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
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.
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
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).
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
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
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.
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.
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.
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.