Fluke GFS2102 User Manual

GFS2102™

Gravimetric Flow Standard

Operation and Maintenance Manual

GFS2102™ OPERATION AND MAINTENANCE MANUAL

Pressurized gases are potentially hazardous. Energy stored in these gases can be released unexpectedly and with extreme force. Pressurized 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, a

Fluke Company 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, GFS2102, GFS Tools, AMH, LCM, MFC-CB, molbloc and molbox are trademarks, registered and otherwise, of DH Instruments, a Fluke Company

Swagelok and Nupro are registered trademarks of the Swagelok Company. Krytox is a registered trademark of the Dupont de Nemours Company. Windows, Excel, Word are registered trademarks of the Microsoft Corporation.

Products described in this manual are manufactured under international patents and one or more of the following U.S. patents: 6,701,791, 5,142,483, 5,257,640, 5,331,838, 5,445,035. Other U.S. and international patents pending.

Document No. 550149a 071129 Printed in the USA

AABBLLEE OOFF

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TABLE OF CONTENTS ...............................................................I

TABLES................................................................................ VII

FIGURES................................................................................IX

ABOUT THIS MANUAL........................................................... XIII

1. INTRODUCTION ................................................................. 1

1.1 SPECIFICATIONS ...................................................................................................................................1

1.1.1 GFS2102 GENERAL SPECIFICATIONS.......................................................................................................1

1.1.2 GFS2102 MASS BALANCE SPECIFICATIONS ...........................................................................................2

1.1.3 LCM AMBIENT CONDITIONS MEASUREMENT SPECIFICATIONS...........................................................2

1.1.3.1 PRT BALANCE AMBIENT TEMPERATURE MEASUREMENT ................................................................2

1.1.3.2 TH PROBE REFERENCE GAS CYLINDER SURROUNDINGS AMBIENT CONDITION

1.1.3.3 INFRARED PROBE REFERENCE GAS CYLINDER SURFACE TEMPERATURE MEASUREMENT.....2

1.1.3.4 AMBIENT CONDITIONS MEASUREMENT...............................................................................................2

1.1.3.5 BALANCE READING TIME MEASUREMENT...........................................................................................2

1.1.4 MFC-CB SPECIFICATIONS..........................................................................................................................3

1.1.5 FLOW MEASUREMENT SPECIFICATIONS.................................................................................................3

MEASUREMENT .......................................................................................................................................2

2. SYSTEM OVERVIEW ........................................................... 5

2.1 BALANCE AND AMH-GFS2102..............................................................................................................6

2.2 REFERENCE GAS CYLINDER ASSEMBLY...........................................................................................8

2.2.1 REFERENCE GAS CYLINDER.....................................................................................................................8

2.2.2 CYLINDER SUPPORT...................................................................................................................................9

2.2.3 REFERENCE GAS CYLINDER CONNECTOR...........................................................................................10

2.2.4 REGULATOR ASSEMBLY..........................................................................................................................11

2.2.5 REFERENCE GAS CYLINDER CASE........................................................................................................11

2.3 GFS DRAFT ENCLOSURE AND VIBRATION ISOLATION TABLE.....................................................12

2.4 LABORATORY CONDITIONS MONITOR (LCM)..................................................................................13

2.5 MFC-CB .................................................................................................................................................13

2.6 GFS TOOLS...........................................................................................................................................14

2.7 HEAT EXCHANGER..............................................................................................................................14

2.8 GFS-FS REFERENCE GAS CYLINDER FILL STATION......................................................................14

2.9 MASS FLOW CONTROLLERS .............................................................................................................14

2.10 MOLBLOC MOLSTICS (OPTIONAL)....................................................................................................15

2.11 MASS SET (OPTIONAL).......................................................................................................................15

3. INSTALLATION ................................................................ 17

3.1 UNPACKING AND INSPECTION ..........................................................................................................17

3.1.1 GRANITE VIBRATION ISOLATION TABLE AND STAND..........................................................................17

3.1.2 GFS DRAFT ENCLOSURE AND SYSTEM ACCESSORIES......................................................................18

3.1.3 LABORATORY CONDITIONS MONITOR...................................................................................................19

3.1.4 MFC-CB .......................................................................................................................................................19

3.1.5 GFS-FS REFERENCE GAS CYLINDER FILL STATION............................................................................19

3.1.6 GFS MASS BALANCE.................................................................................................................................20

3.1.7 AMH-GFS2102.............................................................................................................................................20

3.1.8 REFERENCE GAS CYLINDER ASSEMBLIES...........................................................................................21

3.1.9 SYSTEM CONTROLLER.............................................................................................................................22

GFS2102™ OPERATION AND MAINTENANCE MANUAL

3.1.10 MS-2102-0.7 MASS SET OR MS-2102-CAR MASS CARRIER..................................................................23

3.1.11 MOLSTICS...................................................................................................................................................23

3.2 SITE REQUIREMENTS..........................................................................................................................23

3.2.1 GFS2102 SYSTEM ......................................................................................................................................23

3.2.2 GFS-FS REFERENCE GAS CYLINDER FILL STATION............................................................................25

3.3 SETUP ...................................................................................................................................................26

3.3.1 POSITION THE VIBRATION ISOLATION TABLE......................................................................................26

3.3.2 INSTALL DRAFT ENCLOSURE ON VIBRATION ISOLATION TABLE......................................................27

3.3.3 SETUP LCM.................................................................................................................................................28

3.3.4 SETUP MFC-CB ..........................................................................................................................................29

3.3.5 SET UP THE SYSTEM CONTROLLER (PC) ..............................................................................................29

3.3.6 VERIFY GFS CALIBRATION DATA............................................................................................................29

3.3.7 ASSEMBLE REFERENCE GAS CYLINDER(S)..........................................................................................30

3.3.8 ENTER REFERENCE GAS CYLINDER DATA...........................................................................................32

3.3.9 INSTALLATION OF REFERENCE MASS ON MASS PLATE.....................................................................32

3.3.10 INITIAL BALANCE AND AMH BASE SETUP.............................................................................................34

3.3.11 SETUP BALANCE LOCATION....................................................................................................................35

3.3.12 AMH POSITION FINE ADJUSTMENT.........................................................................................................36

3.3.13 SETUP PROBE LOCATIONS......................................................................................................................38

3.3.14 PREPARE THE HEAT EXCHANGER..........................................................................................................39

3.3.15 CONNECT THE DUT FLOW PATH.............................................................................................................40

3.3.16 CONNECT GAS CONVEYANCE LOOP......................................................................................................41

4. OPERATION..................................................................... 43

4.1 GENERAL OPERATING PRINCIPLES .................................................................................................43

4.1.1 GFS2102 MEASUREMENT PRINCIPLE.....................................................................................................43

4.1.2 GAS DEPENDENT MASS RANGES AND CYLINDER SIZE SELECTION ................................................44

4.1.3 AUTOZERO..................................................................................................................................................46

4.1.4 GFS2102 DATA COLLECTION METHODS AND CONVENTIONS............................................................46

4.1.4.1 ACCUMULATIONS ..................................................................................................................................46

4.1.4.2 SAMPLES ................................................................................................................................................46

4.1.4.3 AVERAGES AND BEST FITS..................................................................................................................47

4.1.5 SETTINGS FOR FLOW SAMPLING............................................................................................................47

4.1.5.1 SETTING UP STARTING AND ENDING SAMPLE TOLERANCE...........................................................48

4.2 MANUAL GFS TOOLS OPERATION....................................................................................................48

4.2.1 READING THE BALANCE...........................................................................................................................48

4.2.2 AMH OPERATION.......................................................................................................................................49

4.2.3 BALANCE ZERO AND SPAN ADJUSTMENT............................................................................................49

4.3 REFERENCE GAS CYLINDER FILLING ..............................................................................................49

4.3.1 TRANSPORTING THE REFERENCE GAS CYLINDER ASSEMBLY.........................................................49

4.3.2 EVACUATING AND RINSING .....................................................................................................................50

4.3.3 CONNECTING TO GFS-FS .........................................................................................................................50

4.3.4 FILLING THE CYLINDER............................................................................................................................51

4.4 CONSIDERATIONS FOR MAKING RELIABLE MEASUREMENTS.....................................................53

4.4.1 COOLING AND CONDENSATION AT HIGH FLOW...................................................................................53

4.4.2 STABILITY OF AMBIENT CONDITIONS....................................................................................................53

4.4.3 COMPARING REFERENCE AND DUT MEASUREMENTS USING FLOW VS. MASS CALCULATIONS 54

4.4.4 LEAKS .........................................................................................................................................................54

4.4.4.1 LEAK TEST OPTION IN A TEST DEFINITION........................................................................................55

4.4.4.2 SEMI-AUTOMATED LEAK TEST.............................................................................................................55

4.4.4.3 SEMI-AUTOMATED LEAK TEST TO MANUAL ISOLATION POINT ......................................................55

4.4.5 FLOW CONTROL AND STABILITY............................................................................................................56

TABLE OF CONTENTS

5. GFS TOOLS SOFTWARE ................................................... 57

5.1 MAIN DISPLAY AND FEATURES.........................................................................................................57

5.1.1 OVERVIEW..................................................................................................................................................57

5.1.2 MAIN MENU BAR........................................................................................................................................57

5.1.2.1 [RUN]........................................................................................................................................................57

5.1.2.2 [SETUP] ...................................................................................................................................................58

5.1.2.3 [TOOLS] ...................................................................................................................................................58

5.1.2.4 [DATA]......................................................................................................................................................58

5.1.2.5 [WINDOW]................................................................................................................................................59

5.1.2.6 [HELP]......................................................................................................................................................59

5.1.3 STATUS BAR...............................................................................................................................................59

5.1.4 MAIN TOOLBAR..........................................................................................................................................60

5.1.4.1 RUN TEST TOOLS ..................................................................................................................................60

5.1.4.2 RUN DISPLAY TOOLS ............................................................................................................................60

5.1.4.3 DATA ACQUISITION TOOLS ..................................................................................................................61

5.1.5 RUN SCREENS ...........................................................................................................................................63

5.1.5.1 OVERVIEW..............................................................................................................................................63

5.1.5.2 GFS RUN SCREEN .................................................................................................................................64

5.1.5.3 GFS DIAGNOSTICS RUN SCREEN........................................................................................................68

5.1.5.4 BALANCE OUTPUT RUN SCREEN........................................................................................................70

5.1.5.5 AMBIENT CONDITIONS RUN SCREEN.................................................................................................71

5.1.5.6 DUT/REFERENCE COMPARISON RUN SCREEN.................................................................................72

5.1.5.7 DEVICE OUTPUT RUN SCREEN............................................................................................................73

5.1.5.8 SPY WINDOWS.......................................................................................................................................74

5.1.5.9 MOLBOX OUTPUT RUN SCREEN..........................................................................................................75

5.1.5.10 TARE MOLBOX........................................................................................................................................77

5.1.5.11 MFC-CB RUN SCREEN...........................................................................................................................78

5.1.5.12 DATA GRID RUN SCREEN.....................................................................................................................79

5.1.5.13 DATA PLOT RUN SCREEN.....................................................................................................................79

5.2 [TOOLS] MENU.....................................................................................................................................80

5.2.1 OVERVIEW..................................................................................................................................................80

5.2.2 [OPTIONS]...................................................................................................................................................80

5.2.2.1 [RUN TEST] TAB......................................................................................................................................80

5.2.2.2 [INITIALIZE TEST] TAB............................................................................................................................83

5.2.2.3 [END TEST] TAB......................................................................................................................................84

5.2.2.4 [DATA FILE] TAB .....................................................................................................................................85

5.2.2.5 [DATA GRID] TAB....................................................................................................................................87

5.2.3 [UNIT OF MEASURE CONVERTER] ..........................................................................................................89

5.2.4 [REMOTE COMMUNICATIONS].................................................................................................................89

5.2.5 [PROCESS GAS EDITOR]..........................................................................................................................90

5.2.6 [CHANGE GFS AMH STATE]......................................................................................................................91

5.2.7 [PC TIMER CALIBRATION] ........................................................................................................................91

5.3 [DATA] MENU........................................................................................................................................91

5.3.1 OVERVIEW..................................................................................................................................................91

5.3.2 [VIEW DATA FILE]......................................................................................................................................91

5.3.3 [PLOT DATA]...............................................................................................................................................93

5.3.3.1 PLOT TOOLBAR......................................................................................................................................93

5.3.3.2 PLOT OPTIONS MENU ...........................................................................................................................94

5.3.3.3 CREATE/EDIT PLOTS.............................................................................................................................94

5.3.3.4 PLOT POINTS..........................................................................................................................................96

5.3.4 [REPORT DATA].........................................................................................................................................98

5.4 DATA FILES ..........................................................................................................................................99

5.4.1 OVERVIEW..................................................................................................................................................99

5.4.2 DATA FILE CREATION ...............................................................................................................................99

5.4.3 NAMING AND STORING DATA FILES.......................................................................................................99

5.4.4 DATA FILE STRUCTURE..........................................................................................................................100

5.5 [SETUP] MENU ...................................................................................................................................102

5.5.1 OVERVIEW................................................................................................................................................102

5.5.1.1 SETUP SELECTOR...............................................................................................................................102

5.5.1.2 EDITOR TOOLBAR................................................................................................................................102

5.5.2 [SETUP], [TEST]........................................................................................................................................104

5.5.2.1 CREATING TEST DEFINITIONS...........................................................................................................104

5.5.2.2 EDITING TEST DEFINITIONS...............................................................................................................105

5.5.2.3 TEST POINT SEQUENCE.....................................................................................................................105

5.5.2.4 [PRE-TEST] TAB....................................................................................................................................105

5.5.2.5 [CONTROL]............................................................................................................................................107

5.5.2.6 [DATA]....................................................................................................................................................108

5.5.2.7 [AUTOZERO]..........................................................................................................................................110

GFS2102™ OPERATION AND MAINTENANCE MANUAL

5.5.2.8 [OPTIONS] .............................................................................................................................................111

5.5.2.9 [COMMENT]...........................................................................................................................................112

5.5.3 [DUT ].........................................................................................................................................................113

5.5.3.1 [HEADER] TAB ......................................................................................................................................114

5.5.3.2 [CALIBRATION] TAB..............................................................................................................................116

5.5.3.3 [COMMUNICATIONS] TAB....................................................................................................................117

5.5.3.4 REMOTE COMMAND EDITOR..............................................................................................................120

5.5.3.5 [OUTPUT] TAB.......................................................................................................................................125

5.5.3.6 [COMMENT] TAB...................................................................................................................................128

5.5.4 [SUPPORT HARDWARE]..........................................................................................................................129

5.5.5 [REFERENCE GAS CYLINDER]...............................................................................................................129

5.5.6 [CONFIGURATION]...................................................................................................................................131

5.5.6.1 [SYSTEM]...............................................................................................................................................131

5.5.6.2 GFS AMH...............................................................................................................................................133

5.5.6.3 [LIMITS]..................................................................................................................................................134

5.5.6.4 [LCM]......................................................................................................................................................135

5.5.6.5 [BALANCE].............................................................................................................................................136

5.5.6.6 [INTERFACE].........................................................................................................................................137

5.5.7 [CALIBRATION].........................................................................................................................................138

5.5.7.1 [TIME/MASS]..........................................................................................................................................138

5.5.7.2 [AMBIENT] .............................................................................................................................................139

5.5.7.3 [TH PROBE #2]......................................................................................................................................140

5.5.7.4 [TH PROBE #3]......................................................................................................................................141

5.5.7.5 [EXTERNAL PRT] ..................................................................................................................................141

5.5.7.6 [IR PROBE] ............................................................................................................................................142

5.6 [RUN] MODES.....................................................................................................................................142

5.6.1 RUN TEST..................................................................................................................................................143

5.6.2 RUN MANUAL TEST.................................................................................................................................147

5.6.3 RUN DIAGNOSTIC TEST..........................................................................................................................149

5.7 CALCULATIONS .................................................................................................................................149

5.7.1 OVERVIEW................................................................................................................................................149

5.7.2 ERRORS....................................................................................................................................................149

5.7.3 TOLERANCE.............................................................................................................................................150

5.7.4 AUTOZERO CORRECTION ......................................................................................................................150

5.7.5 REFERENCE CYLINDER BUOYANCY.....................................................................................................151

5.7.6 FULLY COMPENSATED MASS................................................................................................................153

5.7.7 AVERAGE FLOW......................................................................................................................................154

5.7.8 BEST FIT FLOW........................................................................................................................................154

5.7.9 INTEGRATED MASS.................................................................................................................................155

5.7.10 %READING GFS TOLERANCE................................................................................................................155

5.7.11 SAMPLE RATE..........................................................................................................................................157

6. GENERAL MAINTENANCE, ADJUSTMENTS, AND STORAGE .159

6.1 SUMMARY...........................................................................................................................................159

6.2 AMH-GFS2102 PLATE POSITIONING POSTS LUBRICATION.........................................................159

6.3 REFERENCE GAS CYLINDER ALIGNMENT.....................................................................................160

6.3.1 CHECK REFERENCE GAS CYLINDER ALIGNMENT.............................................................................160

6.3.2 ALIGNMENT OF THE REFERENCE GAS CYLINDER.............................................................................161

6.4 PREPARING THE REFERENCE GAS CYLINDER ASSEMBLY FOR SHIPMENT OR LONG TERM

STORAGE............................................................................................................................................162

6.5 REFERENCE GAS CYLINDER HYDROSTATIC TESTING................................................................163

6.6 REMOVING OR REASSEMBLING THE CYLINDER CARRIER.........................................................163

6.6.1 REMOVING THE CYLINDER CARRIER...................................................................................................164

6.6.2 REASSMBLING THE CARRIER TO THE CYLINDER..............................................................................164

6.7 CHECK/CHANGE FLUID IN HEAT EXCHANGER..............................................................................165

6.8 RELEVEL SYSTEM SURFACES.........................................................................................................165

6.9 LEAK CHECK THE FLOW PATH........................................................................................................165

TABLE OF CONTENTS

7. MAINTENANCE OF TRACEABILITY AND RECALIBRATION ...167

7.1 PRINCIPLES OF GFS2102 TRACEABILITY MAINTENANCE...........................................................167

7.2 [PC TIMER CALIBRATION] ................................................................................................................167

7.3 MOLBOX AUTOZ AND TARE OPERATIONS.....................................................................................167

7.4 REFERENCE MASS RECALIBRATION..............................................................................................167

7.5 LABORATORY CONDITIONS MONITOR (LCM) RECALIBRATION.................................................168

7.5.1 OVERVIEW................................................................................................................................................168

7.5.2 AS RECEIVED DATA REVIEW .................................................................................................................169

7.5.3 LCM TIME VERIFICATION OR ADJUSTMENT........................................................................................169

7.5.3.1 PRINCIPLE ............................................................................................................................................169

7.5.3.2 LCM TIME VERIFICATION....................................................................................................................169

7.5.3.3 LCM TIME ADJUSTMENT.....................................................................................................................170

7.5.3.4  EQUIPMENT REQUIRED.................................................................................................................170

7.5.3.5  OPERATION.....................................................................................................................................170

7.5.4 AMBIENT P, T, H SENSOR ADJUSTMENT.............................................................................................171

7.5.4.1 PRINCIPLE ............................................................................................................................................171

7.5.4.2 ENCLOSURE PRESSURE SENSOR....................................................................................................172

7.5.4.3 AMBIENT TEMPERATURE SENSOR...................................................................................................173

7.5.4.4 RELATIVE HUMIDITY SENSOR............................................................................................................174

7.5.5 TH PROBE ADJUSTMENT........................................................................................................................175

7.5.5.1 TH PROBE TEMPERATURE SENSOR.................................................................................................175

7.5.5.2 TH PROBE RELATIVE HUMIDITY SENSOR........................................................................................176

7.5.6 EXTERNAL PRT TEMPERATURE ADJUSTMENT ..................................................................................177

7.5.7 INFRARED (IR) CYLINDER TEMPERATURE ADJUSTMENT.................................................................178

7.5.8 LCM OHMIC MEASUREMENT SYSTEM VERIFICATION........................................................................179

7.5.9 STANDARD RESISTOR MEASUREMENT AND ADJUSTMENT.............................................................181

7.5.10 LCM REMOTE COMMAND FOR AUTOMATION......................................................................................182

7.6 MOLBOX RECALIBRATION...............................................................................................................183

7.7 MFC-CB RECALIBRATION.................................................................................................................183

7.8 BALANCE RECALIBRATION..............................................................................................................183

7.8.1 INTERNAL BALANCE CALIBRATION......................................................................................................183

7.8.2 GFS TOOLS ZERO AND SPAN CALIBRATION.......................................................................................183

7.8.3 VERIFICATION BY MASS CARRIER........................................................................................................184

8. TROUBLESHOOTING .......................................................185

8.1 OVERVIEW..........................................................................................................................................185

9. APPENDIX ......................................................................187

9.1 GLOSSARY .........................................................................................................................................187

9.2 TYPICAL TEST SETUPS.....................................................................................................................188

9.3 WARRANTY STATEMENT..................................................................................................................189

GFS2102™ OPERATION AND MAINTENANCE MANUAL

OOTTEES

TABLES & FIGURES

AABBLLEES

Table 1. GFS2102 packing list...................................................................................................................17

Table 2. Draft enclosure and system accessories list ...............................................................................18

Table 3. LCM parts list................................................................................................................................19

Table 4. MFC-CB parts list..........................................................................................................................19

Table 5. GFS-FS fill station parts list ..........................................................................................................20

Table 6. GFS mass balance parts list........................................................................................................20

Table 7. AMH-GFS2102 parts list...............................................................................................................21

Table 8. Reference gas cylinder assemblies’ parts lists............................................................................22

Table 9. MS-2102-0.7 mass set parts list..................................................................................................23

Table 10. MS-2102-CAR mass carrier parts list........................................................................................23

Table 11: Maximum mass available for flow testing for various GFS2102 supported gases.....................45

Table 12. Main Toolbar, Run Test Tools ...................................................................................................60

Table 13. Main Toolbar, Run Display Tools...............................................................................................61

Table 14. <Control> Toolbar, Data Acquisition Options ............................................................................ 62

Table 15. GFS Control Panel Fields..........................................................................................................65

Table 16. GFS System Display Fields.......................................................................................................67

Table 17. GFS Control Toolbar icons .........................................................................................................67

Table 18. GFS Diagnostics Fields .............................................................................................................69

Table 19. Balance Output Run Screen Fields ..........................................................................................70

Table 20. GFS Ambient Conditions Run Screen Fields ...........................................................................71

Table 21. DUT/Reference Comparison Run Screen Fields......................................................................73

Table 22. Spy Window Information............................................................................................................75

Table 23. <molbox Output> Run Screen Fields.........................................................................................76

Table 24. Tare molbox Fields ....................................................................................................................78

Table 25. MFC CB Fields...........................................................................................................................79

Table 26. Options, [Run Test] Tab Fields..................................................................................................81

Table 27. Options, [Initialize Test] Tab Fields............................................................................................83

Table 28. Options, [End Test] Tab Fields ..................................................................................................85

Table 29. Options, [Data File] Tab Fields ..................................................................................................86

Table 30. Options, [Data Grid] Tab Selections..........................................................................................89

Table 31. Data File Viewer Options...........................................................................................................92

Table 32. Data Plot Toolbar.......................................................................................................................93

Table 33. Custom Plot Editor Fields ..........................................................................................................95

Table 34. Plot Points General Tab Fields..................................................................................................97

Table 35. Plot Points Best Fit Tab Fields...................................................................................................98

Table 36. Data Files Types........................................................................................................................99

Table 37. Data File Data Field Optional Selections.................................................................................100

Table 38. Data File Structure...................................................................................................................101

Table 39. Editor Toolbar Features...........................................................................................................103

Table 40. Test Editor, [Pre-Test] Tab, <Leak Test> Fields......................................................................106

Table 41. Test Definition Editor, Point Sequence Tab, [General] Child Tab Fields.................................107

Table 42. Test Definition Editor [Data] Tab Fields...................................................................................109

Table 43. Test Definition Editor [AutoZero] Tab Fields............................................................................111

Table 44. Test Definition Editor [Options] Tab Fields..............................................................................112

Table 45. DUT Editor, [Header] Tab Fields .............................................................................................114

GFS2102™ OPERATION AND MAINTENANCE MANUAL

Table 46. Device Editor, [Calibration] Tab Fields ....................................................................................117

Table 47. Device Editor, [Communications] Tab Fields..........................................................................119

Table 48. Remote Command Editor, [Command] Tab Fields..................................................................123

Table 49. Remote Command Editor, [Global Settings] Tab Options.......................................................124

Table 50. DUT Editor, [Output] Tab Fields ..............................................................................................126

Table 51. Tolerance Type Choices..........................................................................................................127

Table 52. Device Type Options................................................................................................................129

Table 53. Reference Cylinder Editor Fields.............................................................................................130

Table 54. GFS Configuration Editor [System] Tab Fields........................................................................132

Table 55. GFS Configuration Editor [GFS AMH] Tab Fields ...................................................................133

Table 56. GFS Configuration Editor [Limits] Tab Fields .......................................................................... 134

Table 57. GFS Configuration Editor [LCM] Tab Fields............................................................................135

Table 58. GFS Configuration Editor [Balance] Tab .................................................................................136

Table 59. GFS Configuration Editor [Interface] Tab Fields......................................................................137

Table 60. Calibration Editor [Time/Mass] Tab Fields...............................................................................138

Table 61. Calibration Editor [Ambient] Tab Fields...................................................................................139

Table 62. Calibration Editor [TH Probe #2] and [TH Probe #3] Tab Fields .............................................140

Table 63. Calibration Editor [External PRT] Tab Fields...........................................................................142

Table 64. Calibration Editor [IR Probe] Tab Fields..................................................................................142

Table 65. Mechanical maintenance procedures......................................................................................159

Table 66. Troubleshooting checklist ........................................................................................................185

Table 67. DHI Authorized Service Providers ...........................................................................................189

TABLES & FIGURES

IIGGUURREES

Figure 1. GFS2102 system.......................................................................................................................... 5

Figure 2. Reference gas cylinder resting on GFS balance and AMH-GFS2102.........................................6

Figure 3. AMH reference mass plate...........................................................................................................7

Figure 4. Balance mass tray supporting the reference gas cylinder ...........................................................7

Figure 5. Reference gas cylinder assembly...................................................................................................8

Figure 6. 1.5 liter and 1.1 liter reference gas cylinder assemblies .............................................................. 9

Figure 7. Reference gas cylinder support..................................................................................................10

Figure 8. Reference gas cylinder connector..............................................................................................10

Figure 9. GFS draft enclosure on vibration isolation table......................................................................... 12

Figure 10. Laboratory Conditions Monitor .................................................................................................13

Figure 11. GFS-FS Reference gas cylinder fill station ..............................................................................14

Figure 12. Typical layout of overall GFS2102 system at site of use..........................................................25

Figure 13. Installation of draft enclosure doors..........................................................................................28

Figure 14. LCM rear panel connections.....................................................................................................28

Figure 15. Reference gas cylinder assembly...............................................................................................30

Figure 16. Reference gas cylinder connector............................................................................................31

Figure 17. Regulator assembly position before and after tightening.........................................................32

Figure 18. Reference Mass Legs (Spherical (x 2) and Flat)......................................................................32

Figure 19. Location of balance positioning bracket mounting holes..........................................................34

Figure 20. GFS balance rear panel connections.......................................................................................34

Figure 21. GFS balance inside AMH with mass tray installed..................................................................35

Figure 22. Checking height and level of gas conveyance loop connections using loop alignment tool....36

Figure 23. Reference Gas Cylinder resting on balance. AMH top plate installed; reference

Figu r e 2 4 . View of cylinder support legs through AMH top plate. ...........................................................37

Figu r e 25 . Temperature probe positions around reference gas cylinder. .................................................39

Figure 26: Heat Exchanger, Low ................................................................................................................39

Figure 27: Heat Exchanger unassembled ..................................................................................................40

Figure 28: Single, Low flow molstic.............................................................................................................40

Figu r e 2 9 . GFS-FS reference gas cylinder fill station connections............................................................50

Figure 30. Reference gas cylinder connector..............................................................................................51

Figure 31. <Status Bar>.............................................................................................................................59

Figure 32. Test Status................................................................................................................................59

Figure 33. Progress Indicator.....................................................................................................................59

Figure 34. Main Toolbar - Display while idle..............................................................................................60

Figure 35. Manual Averaging Options .......................................................................................................62

Figure 36. <Average Setup>......................................................................................................................63

Figure 37. GFS Run Screen ......................................................................................................................64

Figure 38: GFS Control Panel section of GFS Run Screen .......................................................................65

Figure 39: GFS System Display section of GFS Run Screen ....................................................................66

Figure 40. GFS Control Toolbar section of GFS Run Screen ...................................................................67

Figure 41. GFS Diagnostics Run Screen...................................................................................................69

Figure 42. Balance Output Run Screen....................................................................................................70

Figure 43. GFS Ambient Conditions Run Screen.....................................................................................71

Figure 44. DUT/Reference Comparison Run Screen...............................................................................72

mass plate uninstalled.............................................................................................................37

GFS2102™ OPERATION AND MAINTENANCE MANUAL

Figure 45. Device Output Run Screen.......................................................................................................74

Figure 46. Spy Window Screen .................................................................................................................74

Figure 47. <molbox Output> Run Screen..................................................................................................75

Figure 48. molbox Output Run Screen in Tare Mode................................................................................77

Figure 49. MFC-CB Run Screen................................................................................................................78

Figure 50. Data Grid Run Screen ..............................................................................................................79

Figure 51. Data Plot Run Screen...............................................................................................................80

Figure 52. Options, [Run Test] Tab............................................................................................................81

Figure 53. Options, [Initialize Test] Tab.....................................................................................................83

Figure 54. Options, [End Test] Tab............................................................................................................84

Figure 55. Options, [Data File] Tab............................................................................................................86

Figure 56. Options, [Data Grid] Tab...........................................................................................................88

Figure 57. Direct Remote Communication.................................................................................................90

Figure 58. Change GFS AMH State ..........................................................................................................91

Figure 59. Data File Viewer .......................................................................................................................92

Figure 60. [Data], [Plot Data File] Screen..................................................................................................93

Figure 61. Custom Plot Editor....................................................................................................................95

Figure 62. Plot Points display ....................................................................................................................97

Figure 63. Plot Points Best Fit Tab............................................................................................................98

Figure 64. Setup Selector ........................................................................................................................102

Figure 65. Editor Toolbar .........................................................................................................................103

Figure 66. Test Definition Editor, Point Sequence...................................................................................105

Figure 67. Test Definition Editor [Control] Tab ........................................................................................107

Figure 68. Test Definition Editor [Data] Tab ............................................................................................109

Figure 69. Test Definition Editor [AutoZero] Tab.....................................................................................110

Figure 70. Test Definition Editor [Options] Tab........................................................................................111

Figure 71. Test Definition Editor, [Comment] Tab ...................................................................................113

Figure 72. DUT Editor, [Header] Tab.......................................................................................................114

Figure 73. DUT Editor, [Calibration] Tab .................................................................................................116

Figure 74. Date Selection ........................................................................................................................117

Figure 75. DUT Definition Editor [Communications] Tab.........................................................................118

Figure 76. Remote Command Editor.......................................................................................................121

Figure 77. DUT Device Edit [Output] Tab................................................................................................125

Figure 78. %Reading Tolerance..............................................................................................................127

Figure 79. %Span Tolerance...................................................................................................................127

Figure 80. %Span or %Reading (Greater of)...........................................................................................128

Figure 81. %Span + %Reading ...............................................................................................................128

Figure 82. DUT Device Edit [Comment] Tab ...........................................................................................129

Figure 83. Reference Cylinder Editor ......................................................................................................130

Figure 84. GFS Configuration [System] Tab............................................................................................131

Figure 85. GFS Configuration [GFS AMH] Tab.......................................................................................133

Figure 86. GFS Configuration [Limits] Tab ..............................................................................................134

Figure 87. GFS Configuration [LCM] Tab................................................................................................135

Figure 88: Remote interface settings window...........................................................................................136

Figure 89. GFS Configuration [Balance] Tab...........................................................................................136

Figure 90. GFS Configuration [Interface] Tab..........................................................................................137

Figure 91. Calibration [Time/Mass] Tab...................................................................................................138

Figure 92. Calibration [Ambient] Tab.......................................................................................................139

Figure 93. Calibration [TH Probe #2] Tab................................................................................................140

Figure 94. Calibration [TH Probe #3] Tab................................................................................................141

TABLES & FIGURES

Figure 95. Calibration [External PRT] Tab...............................................................................................141

Figure 96. Calibration [IR Probe] Tab......................................................................................................142

Figure 97: Run Test - Setup Test Definition window ................................................................................143

Figure 98: Run Test - Select Test Definition Window...............................................................................144

Figure 99: Run Test - Select DUTs window..............................................................................................144

Figure 100: Run Test - Configure DUT Device window............................................................................145

Figure 101: Run Test - Setup Flow Controller window.............................................................................145

Figure 102: Run Test - Configure MFC Device window...........................................................................146

Figure 103: Run Test - Initializing Test Instruments window....................................................................146

Figure 104: Run Manual Test - Setup Manual Test window.....................................................................147

Figure 105: Accumulation Sample Setup window .................................................................................... 148

Figure 106: US-DOT and European Reference Gas Cylinder labels....................................................... 163

Figure 107. Reference gas cylinder carrier..............................................................................................164

Figure 108. Time Calibration window .......................................................................................................170

Figure 109. Calibration Time/Mass tab.....................................................................................................171

Figure 110: LCM default front panel display.............................................................................................172

Figure 111. Ambient sensors adjustment tab...........................................................................................173

Figure 112: LCM TH probe front panel display.........................................................................................175

Figure 113. TH Probe #2 adjustment tab..................................................................................................176

Figure 114. External PRT adjustment tab.................................................................................................178

Figure 115. LCM IR probe front panel display..........................................................................................179

Figure 116. IR Probe adjustment tab........................................................................................................179

Figure 117. View of main board socket J19 or top view of calibration cable...........................................182

GFS2102™ OPERATION AND MAINTENANCE MANUAL

OOTTEES

ABOUT THIS MANUAL

BBOOUUTT

This manual provides the information necessary to operate a GFS2102 gravimetric mass flow calibration standard to make gas mass flow measurements. It also provides additional recommendations and information to help you optimize use of the GFS2102 system and take full advantage of it’s many features and functions.

Before using the manual, take a moment to familiarize yourself with the Table of Contents structure. Set up of a GFS2102 system should not be attempted without using Section 3. All first time GFS2102 users should read Section 4. There is a glossary of common terms in Section 9.1, a troubleshooting guide in Section 1, and a chart of typical test settings in Section

(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 or objects (e.g., [RANGE]) on an instrument front panel keypad or in a software user interface.

HHIISS

AANNUUAAL

Manual Conventions

< > indicates instrument front panel screen displays or labels in a software user interface (e.g., <1yes>)

GFS2102™ OPERATION AND MAINTENANCE MANUAL

OOTTEES

1. INTRODUCTION

11.

GFS2102 measures gas mass flow by measuring the loss of mass from a reference gas cylinder over a measured period of time. The reference gas cylinder assembly rests on the GFS mass balance and flow is transmitted from the cylinder through a flow path designed to have minimal effect on the balance mass measurement. Balance mass and time measurements and a number of ambient conditions are all read using a component of the GFS2102 system called LCM, the Laboratory Conditions Monitor. Since test times may be long, a special automated mass handling platform is used to load a fixed reference mass on the GFS balance at intervals thoughout the test to quantify and remove any effects from balance drift over time.

All measurement functions of the GFS2102 system are operated by a system controller (personal computer) running GFS Tools software. The system is made up of several individual components working together and controlled by GFS Tools.

NNTTRROODDUUCCTTIIOON

1.1 SPECIFICATIONS

1.1.1 GFS2102 GENERAL SPECIFICATIONS

Power Requirements

Operating Temperature Range Humidity Range

Weight

Granite table and stand

Rest of system

Dimensions

Enclusure on Granite Table w/ stand

Supported Gases

Flow Measurement Range

All other gases

Pressure Connections

outlet flow path from enclosure

Reference Gas Cylinder Pressure Limit CE Conformance

Balance

LCM

MFC-CB

LCM

MFC-CB

GFS-FS

He, H2

100 to 240 VAC, 50 to 60 Hz, 27 W max. consumption 100 to 240 VAC, 50 to 60 Hz, 40 W max. consumption 85 to 264 VAC, 50 to 60 Hz, 36 W max. consumption

15 to 25 °C 5 to 70% RH, non-condensing

320 kg (700 lb) approx. 70 kg (150 lb) approx.

150 cm H x 90 cm W x 60 cm D (58 in. x 36 in. x 24 in.) 8 cm H x 22.5 cm W x 20 cm D (3.1 in. x 8.9 in. x 7.9 in.) 8 cm H x 22.5 cm W x 20 cm D (3.1 in. x 8.9 in. x 7.9 in.)

20 cm H x 41.4 cm W x 20 cm D (7.9 in. x 16.3 in. x 7.9 in.) Nitrogen (N2), Air, Argon (Ar), Carbon Monoxide (CO), Helium (He),

Oxygen (O2), Carbon Dioxide (CO2), Carbon Tetrafluoride (CF4), Ethane (C2H6), Ethylene (C2H4), Fluoroform (CHF3), Hexafluoroethane (C2F6), Hydrogen (H2), Methane (CH4), Nitrous Oxide (N2O), Sulfur Hexafluoride (SF6), Xenon (Xe)

at least: 100 sccm to 10 slm

10 sccm to 10 slm 1/8” Swagelok tube fitting or equivalent, with adaptor to

1/4” Swagelok tube fitting or equivalent 20 MPa (3000 psi)

Available, must be specified.

GFS2102™ OPERATION AND MAINTENANCE MANUAL

1.1.2 GFS2102 MASS BALANCE SPECIFICATIONS

Operating temperature range

Operating humidity (maximum)

Resolution

Mass Uncertainty

15 to 30 °C

70% RH, non-condensing

0.1 mg 10 ppm of span or better

1.1.3 LCM AMBIENT CONDITIONS MEASUREMENT SPECIFICATIONS

1.1.3.1 PRT BALANCE AMBIENT TEMPERATURE MEASUREMENT

Temperature:

Range

Uncertainty

1.1.3.2 TH PROBE REFERENCE GAS CYLINDER SURROUNDINGS

AMBIENT CONDITION MEASUREMENT

Temperature:

Range

Uncertainty

Relative Humidity:

Range

Uncertainty

[°C] 15 to 30

± 0.1

[°C] 15 to 30

± 0.2

5 to 95 %RH ± 10 %RH

1.1.3.3 INFRARED PROBE REFERENCE GAS CYLINDER SURFACE

TEMPERATURE MEASUREMENT

Temperature:

Range

Uncertainty

[°C] 0 to 30

± 2.2

1.1.3.4 AMBIENT CONDITIONS MEASUREMENT

Pressure:

Range

Uncertainty

Temperature:

Range

Uncertainty

Relative Humidity:

Range

Accuracy

[kPa] 70 to 110 ± 0.2

[°C] 15 to 30 ± 1.0

5 to 95 %RH ± 10 %RH

1.1.3.5 BALANCE READING TIME MEASUREMENT

Time:

32 ppm

1. INTRODUCTION

1.1.4 MFC-CB SPECIFICATIONS

ANALOG OUTPUT

Voltage Range

Voltage Accuracy

Voltage Resolution

Current Range

Current Accuracy

Current Resolution

0 to 6.000 VDC ± 0.015 % FS

0.1 mVDC 4 to 20 mA ± 0.025 % FS

0.4 μA

ANALOG INPUT

Voltage Range

Min/Max Measurable Voltage

Voltage Accuracy

Voltage Resolution

Current Range

0 to 6.000 VDC

- 0.25/6.00 VDC ± 0.015 % FS 1 mVDC 4 to 20 mA

1.1.5 FLOW MEASUREMENT SPECIFICATIONS

Repeatability Measurement Uncertainty

less than ± 0.05% of reading less than ± 0.1% of reading

GFS2102™ OPERATION AND MAINTENANCE MANUAL

OOTTEES

2. SYSTEM OVERVIEW

22.

GFS2102 is a primary gravimetric gas flow measurement standard. It is intended for use in calibrating gas flow transfer standards or other flow devices requiring a very low uncertainty reference. GFS2102 is recommended when low uncertainty is the primary requirement of a flow measurement. GFS2102 covers the range of 10 sccm to 10 slm in most gases. All measurement functions of the GFS2102 system are managed by a system controller (personal computer) running GFS Tools software. The system is made up of several individual components working together and controlled by GFS Tools, which is the user interface for the GFS2102 instrument.

YYSSTTEEMM

VVEERRVVIIEEW

Figure 1. GFS2102 system

1. Precision mass balance 8. Catenary gas conveyance loop

2. Reference mass 9. Laboratory conditions monitor

3. AMH-GFS2102 automated mass handler 10. MFC control box

4. IR probe 11. Flow terminal (for device under test)

5. Reference gas cylinder 12. Mass flow controller

6. Ambient conditions probe 13. Device under test

7. Ambient conditions probe

GFS2102 measures gas mass flow by measuring the loss of mass from a reference gas cylinder over a measured period of time. The reference gas cylinder assembly rests on the GFS mass balance that is placed on a vibration isolation table and inside an insulated draft enclosure. Flow is transmitted from the cylinder and out through the enclosure wall in a flow path designed to cause minimal effect on the balance mass measurement.

GFS2102™ OPERATION AND MAINTENANCE MANUAL

In order to mitigate mass measurement errors due to balance drift over time, the balance sits inside an automated mass handling platform assembly, AMH-GFS2102, that allows the cylinder assembly to be lifted off the balance, and a reference mass to be loaded on the balance, without interrupting the flow measurement.

The Laboratory Conditions Monitor (LCM) is a central piece of hardware for GFS system operation. It performs several different functions for the system. These include measurement of temperature under the AMH platform, measuring temperature and humidity surrounding the reference gas cylinder, measuring the temperature of the reference gas cylinder, actuating the AMH platform movement, measuring ambient pressure and recording the precise time at which each balance reading is taken. Another piece of support hardware, MFC-CB is used for sending flow command signals to the flow controllers, and possibly reading the device under test if the device has a voltage output.

2.1 BALANCE AND AMH-GFS2102

GFS2102 measures the changing reference gas cylinder mass using a high precision 2.3 kg range mass balance. It is a mass comparator type balance, so there is no significant deflection of the mass tray while the mass load is placed on it. The balance has a digital serial output which is read by the LCM.

In a typical mass measurement, the balance can be zeroed, or tared, immediately before placement of the mass, and the measurement can be made relatively quickly after zeroing. Since gravimetric gas flow measurements can require up to several hours or days for some gases and flow ranges, the balance’s stability over time and level of influence from surrounding conditions becomes very significant to GFS2101 measurements.

A key to reaching the desired level of uncertainty using GFS2101 is to eliminate or minimize the uncertainty due to drift of the mass balance over time. In order to quantify and correct for the balance drift, a specialized automated mass handling platform called AMH-GFS2102 has been developed to allow the GFS balance to be AutoZeroed at selected intervals during a flow measurement. The AMH alternately lifts the reference gas cylinder assembly off the balance, loads a fixed reference mass in its place for measurement, and returns the reference gas cylinder assembly without interrupting the flow measurement.

Figure 2. Reference gas cylinder resting on GFS balance and AMH-GFS2102

2. SYSTEM OVERVIEW

The reference mass is approximately 2.0 kg, which is close to the mid point between a full 1.1 liter reference gas cylinder and an empty 1.5 liter reference gas cylinder, so that the balance is checked and corrected for drift at a mass load that is close to the cylinder mass being measured. The balance readings are then corrected for any drift that has occurred since the last time a balance zero or AutoZero were checked.

Figure 3. AMH reference mass plate

AMH-GFS2102 lifts the reference gas cylinder vertically only 3 mm when unloading it from the balance so that the gas flow is not disturbed and no unnecessary deflection of the gas conveyance loop takes place. The standard balance mass tray has been replaced with a custom mass tray that uses a three point locating system to assure consistent physical placement of the reference gas cylinder on the balance during and after each balance AutoZero process (see Section 4.1.3).

Figure 4. Balance mass tray supporting the reference gas cylinder

The reference gas cylinder and reference mass are loaded and unloaded from the balance by two AMH plates that are keyed to lift one of the components when the plate is raised and allow it to rest on the balance when the plate is lowered. The plates move vertically along two posts on the AMH base that orient them, and are raised and lowered by three cams on two shafts in the AMH base which contact rollers that support each plate. A small motor is included in the AMH base to turn the shafts, which are actuated by 12V valve drivers in the LCM.

GFS2102™ OPERATION AND MAINTENANCE MANUAL

2.2 REFERENCE GAS CYLINDER ASSEMBLY

The GFS2102 reference gas cylinder assembly is built around a high pressure carbon fiber composite cylinder. In addition to the cylinder itself, the assembly includes a cylinder support, a cylinder connector with fill port and valve, and a two stage welded regulator assembly.

Figure 5. Reference gas cylinder assembly

1. Reference gas cylinder 3. Reference gas cylinder connector

2. Regulator assembly 4. Cylinder support

The reference gas cylinder is a metrological component of the GFS2102 system. Each cylinder assembly is individually tested to determine the internal volume of the assembly. This information, along with the external volume and coefficients of thermal and pressure expansion, allow proper calculation of an air buoyancy correction on the measured mass value and the total mass of test gas available in the cylinder. The characteristics of each cylinder are included on a technical data report that accompanies a new cylinder assembly and must be entered in GFS Tools software (see Sections 3.3.8 and 5.7.5 for more information).

The components of the reference gas cylinder assembly are designed or selected to be possible so that the mass of the test gas makes up a relatively large portion of total measured mass on the balance, allowing sufficient resolution on the measurement of the mass change during the test. The components of the GFS2102 reference gas cylinder assemblies are described below.

light

2.2.1 REFERENCE GAS CYLINDER

The cylinders used for GFS are composite cylinders made with a thin aluminum internal lining, wrapped in carbon fiber in epoxy resin for strength and covered with a fiberglass lining and gel coat finish for resistance to abrasion, impact and UV degradation. The fiber composite design allows them to be lighter than most high pressure cylinders, so a smaller percentage of the total filled cylinder assembly mass comes from the cylinder itself.

2. SYSTEM OVERVIEW

There are two different reference gas cylinder sizes offered with the GFS2102 system, a 1.1 liter cylinder and a 1.5 liter cylinder. The two cylinders are offered to accommodate the greatly varying gas densities that can be used with the system (see Section 4.1.2). The cylinders are rated for a maximum working pressure of 20 MPa (3000 psi) for the 1.1 liter cylinder and 31 MPa (4500 psi) for the 1.5 liter cylinder. During manufacturing, the cylinders undergo a hydraulic pressure test up to 1.5 times the rated operating pressure.

The cylinders are delivered with appropriate labeling to meet European or US-DOT requirements depending on the location of the GFS2102 end user.

Figure 6. 1.5 liter and 1.1 liter reference gas cylinder assemblies

The cylinders’ design life is 15 years from the date of manufacture. At that time, the cylinders should be replaced. Hydrostatic testing should also be performed on the cylinders every 5 years to ensure safe operation.

Do not expose the reference gas cylinder to temperatures above 56 °C (133 °F). If you suspect that a reference gas cylinder has been heated to temperatures of 56 °C or more, it must be hydrostatically retested and fully re-qualified before further use. Reference gas cylinders exposed to or with evidence of exposure to heat in excess of 72 °C (162 °F) must be condemned and removed from service.

Avoid letting the cylinder come in contact with strong solvents or cleaning agents, vehicle fluids or corrosive materials as the composite material may be damaged.

For safety, heat dissipation and to maximize the life of the cylinder, filling of the reference gas cylinder should be performed as described in section 4.3. Also see section 2.8 for an overview on the GFS Fill Station.

2.2.2 CYLINDER SUPPORT

The reference gas cylinder is supported on the GFS balance by a custom assembly whose three legs pass through the two plates of the AMH and rest directly on the balance mass tray.

GFS2102™ OPERATION AND MAINTENANCE MANUAL

The three leg design of the cylinder support and the custom balance tray make up a locating system for the reference gas cylinder so that it is placed on the balance tray in the same way each time it is set down, to optimize the repeatability of mass measurements. The foot of each leg of the cylinder support is a ruby sphere which is press-fit into the steel support leg. The spheres help to minimize friction as the reference gas cylinder assembly is placed on the balance tray and guided into its resting position.

Figure 7. Reference gas cylinder support

The cylinder support is made of stainless steel legs threaded into a machined aluminum body. Six threaded, spring-loaded pins located around the top ring of the cylinder support are used to attach the support to the reference gas cylinder. Rubber pads are used to protect the cylinder from damage where the pins make contact.

2.2.3 REFERENCE GAS CYLINDER CONNECTOR

The reference gas cylinder connector is a threaded cylinder plug that provides the connection to the cylinder’s regulator assembly and also has a built-in fill port and valve so that the cylinder can be filled without removing the regulator assembly.

Figure 8. Reference gas cylinder connector

1. Fill valve 3. Regulator stem port

2. Fill port

2. SYSTEM OVERVIEW

The regulator stem port and the fill port connections are both DH200 coned and threaded connectors. This type of fitting is suitable for pressures beyond the reference gas cylinders maximum operating pressure and the connection can be broken and reconnected many times. The regulator stem port will rarely be disconnected, but the fill port will be used frequently for cylinder refills.

The fill valve is a threaded plug which operates a valve pin with an o-ring seal. The valve opens or closes the flow path to the fill port so that the fill port connection can be broken and reconnected while the cylinder is under pressure. To open the valve, it is not necessary to turn the valve any more than ½ turn. If the valve is fully backed out counter-clockwise while the cylinder is under pressure, the valve could dislodge from the cylinder connector dangerously. The valve is designed to start venting through a side vent approximately 3 turns before release as a warning.

See Section 4.3 for reference gas cylinder filling instructions.

To open the valve, it is not necessary to turn the valve any more than ½ turn. If the valve is fully backed out counter-clockwise while the cylinder is under pressure, the valve could dislodge from the cylinder connector dangerously. The valve is designed to start venting through a side vent approximately 3 turns before release as a warning.

2.2.4 REGULATOR ASSEMBLY

Each reference gas cylinder assembly includes a two-stage pressure regulator assembly to deliver a well-regulated gas flow through the gas conveyance loop and out of the GFS draft enclosure. The regulator assembly is made up of two fixed pressure regulators on a welded assembly that is designed to be centered over the reference gas cylinder and to have a low center of gravity. The center support of the regulator assembly is a solid piece that does not conduct any gas flow. All of the flow follows the flow path to the side and through both regulators. On all reference gas cylinder assemblies, the first stage regulator is set to deliver downstream pressure of 1 MPa (150 psi). On 1.1 liter reference gas cylinder assemblies, the second regulator delivers 690 kPa (100 psi). On 1.5 liter reference gas cylinder assemblies, the second regulator delivers 550 kPa (80 psi).

2.2.5 REFERENCE GAS CYLINDER CASE

All the pieces for the reference gas cylinder assembly are delivered in a custom fill/carry case to provide a convenient way to store and carry the reference cylinder assembly around the laboratory. This case is designed to allow the user to fill the cylinder while it is resting in the case (with the case lid open) and provides adequate ventilation for the cylinder to cool during and after the filling operation. The reference gas cylinder assembly should NOT be shipped or transported for any distance outside the lab in the fill/carry case while the regulator assembly is installed on the cylinder or the cylinder is pressurized. If the unit encounters a significant shock while the reference gas cylinder with fully installed regulator assembly is inside the case, the vertical nipple of the regulator assembly could bend under the weight of the regulators, which may cause alignment problems for the cylinder assembly in the GFS system, and may compromise the strength of the tubing in a high pressure section of the regulator assembly. For assembling the reference gas cylinder, always follow the instructions in section 3.1.8. For filling the cylinder, always follow the instructions in Section

4.3.

GFS2102™ OPERATION AND MAINTENANCE MANUAL

Never ship an assembled or pressurized reference gas cylinder. Always follow the instructions in Section 6.4 for disassembling the reference gas cylinder for shipment.

Never leave a pressurized reference gas cylinder in a sealed case for an extended time. Leave the case unlatched if storing a pressurized cylinder.

2.3 GFS DRAFT ENCLOSURE AND VIBRATION ISOLATION TABLE

The GFS balance, AMH, and reference gas cylinder assembly are operated inside an insulated enclosure to isolate them from air drafts and rapid changes in temperature or humidity.

The entire enclosure is placed on a granite vibration isolation table, which further stabilizes the temperature inside the enclosure. The granite table top measures 600mm x 900mm x 150 mm (23.6” x

35.4” x 5.9”) and has ledges which are used as a connection point for the draft enclosure mounting

brackets. The table top rests on a steel stand.

Figure 9. GFS draft enclosure on vibration isolation table

2. SYSTEM OVERVIEW

There are two pass through openings on the right side of the enclosure. One is for the exit of the flow path tube and ambient pressure tube, and the other is for electrical connections to the balance, AMH and internal temperature and humidity probes.

After the gas travels from the reference gas cylinder and through the gas conveyance loop it passes through a quick connector mounted on a bracket on the inside of the GFS draft enclosure. A tube leading from this connector passes inside the bracket, through an isolation valve, and down through the enclosure pass through opening below. The vertical position of the quick connector on the enclosure bracket is adjustable. The height of the quick connector at the outlet of the reference gas cylinder assembly is different for 1.1 liter and 1.5 liter cylinders and also may not be consistent among cylinders of the same size. Therefore it may be necessary to adjust the quick connector on the on the draft enclosure bracket to keep the ends of the gas conveyance loop level. It is important that the loop ends are level so that no unintended forces are imparted to the cylinder while its mass is being measured.

Three probe positioning arms are mounted on the inside of the back wall of the draft enclosure. The adjustable arms hold the two TH probe devices and IR temperature probe in proper positions relative to the reference gas cylinder assembly to get accurate measurements of the cylinder’s surface and surrounding conditions.

A loop alignment tool is delivered with the GFS draft enclosure to help in positioning the AMH so that the loop takes its ideal natural shape, minimizing the possibility of unintended forces applied to the reference gas cylinder while it is on the balance.

2.4 LABORATORY CONDITIONS MONITOR (LCM)

The LCM is the central data collection component of GFS2102. All GFS balance mass measurements are read by the LCM and the precise time of each balance reading is recorded using LCM’s calibrated on-board timer and passed on to GFS Tools software. Measurements of pressure, temperature and humidity in the vicinity of the reference gas cylinder and balance are needed for GFS Tools to calculate the instantaneous mass of the cylinder, corrected for air buoyancy, throughout the test. All of these measurements are made by the LCM using internal ambient condition measurements and probes that are placed in critical locations inside the GFS draft enclosure.

Figure 10. Laboratory Conditions Monitor

2.5 MFC-CB

MFC-CB is used for controlling flow setpoint signals to mass flow controllers included in the GFS2102 system. It may also be used for reading the output of a device under test that has an analog signal output. Communication with MFC-CB for controlling flow is supported automatically in GFS Tools software. For reading device under test (DUT) output, some configuration of MFC-CB and/or GFS Tools is needed (See Section 5.5.3). See the separate MFC-CB Operation and Maintenance Manual for details on MFC-CB.

GFS2102™ OPERATION AND MAINTENANCE MANUAL

2.6 GFS TOOLS

The user interface for operating GFS2102 is GFS Tools software. GFS Tools handles all collection of data from the GFS system components and devices under test and calculation and reporting of mass flow and errors. Some operating principles of GFS Tools are described in Section 4.1 and 4.2 and GFS Tools is described in detail in Section 5.

2.7 HEAT EXCHANGER

At flows above 1 slm in N2, the calibration gas is discharging from the Reference Gas Cylinder quickly enough that the cooling of the gas from decompression can effect the regulator, MFC, and molbloc(s) downstream of the GFS. This in turn can effect the stability and control of the flow, and ultimately the overall accuracy. To significantly reduce these effects a heat exchanger is used. A fully assembled heat exchanger consists of a 3.2 Qt. stainless steel can filled with water or a water/antifreeze mix with approximately 7-10 feet of ¼” stainless tubing coiled up and submerged in the liquid. For shipping purposes the exchanger is shipped without liquid and needs to be prepared prior to use. Preparation of the heat exchanger is described in Section 3.3.14.

2.8 GFS-FS REFERENCE GAS CYLINDER FILL STATION

A specialized filling station is provided with the GFS2102 system to help users fill the reference gas cylinders safely and slowly with minimal heating of the cylinder. The design of the fill station allows the user to quickly set the desired fill pressure and the cylinder is filled at a slow rate that is controlled by a flow limiter. The user can view the set pressure that the cylinder will ultimately achieve and the current cylinder pressure as it fills.

Figure 11. GFS-FS Reference gas cylinder fill station

See Section 4.3 for details on GFS-FS operation and connections.

2.9 MASS FLOW CONTROLLERS

Four mass flow controllers are included with the GFS-2102 system. There are (1) 10 sccm MFC, (1) 100 sccm MFC, (1) 1 slm MFC, and (1) 10 slm MFC all adjusted to operate in these ranges for N2. These can be used for any gas that they can reasonably operate with by applying the K factors found in GFS Tools. When working with gases other than N2, in most cases a test will have to be sectioned into two or more tests in order to work with multiple MFC’s.

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