Fluke molbox RFM Operating Manual
molbox™ RFM™
Reference
Flow Monitor
(Ver 1.20 and Higher)
Operation and Maintenance Manual
© 2010 Fluke Calibration
Warning
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
© 2010 Fluke Calibration All rights reserved.
Information in this document i s subject to change without not i ce. No part of this docum ent may be reproduced or transmit ted in any
form or by any means, elect ronic or mechanical, for any purpose, without the express writt en permission of Fluke Calibration,
4765 East Beautiful Lane, Phoenix, Arizona 85044-5318 USA.
Fluke Calibration makes sincere efforts to ensure the accuracy and quality of its published materials; however, no warranty,
expressed or implied, is provided. Fl uke Calibration disclaims any respons ibility or liability for any direct or indirect damages
resulting from the use of the inform ation in this manual or products described in it. Mention of any product or brand does not
constitute an endorsem ent by Fluke Calibration of that product or brand. This manual was original ly composed in English and
was subsequently translated into ot her languages. The fi delit y of the t ransl ation c annot be guarant eed. I n cas e of confl ict between
the English version and other language versions, the English version predom i nates.
Products described in thi s manual are manufactured under int ernational patents and one or more of the f ollowing U.S. patents:
5,142,483, 5,257,640, 5,331,838, 5,445,035. Other U.S. and international patents pending.
been instructed in proper safety practices.
Fluke Calibration, FCAL, DH, DHI, molbox, molbox RFM , molbox1, molbox1+, molbloc, molbloc-L, molbloc-S, molstic,
COMPASS, CalTool are tradem ark s, registered and otherwise, of Fluke Corporation.
LabVIEW is registered trademark of National Ins truments Corporation.
Swagelok is a regis t ered trademark of the Swagelok Com pany.
Document No. 3152156
101115
Printed in the USA.
© 2010 Fluke Calibration Page II
Table Of Contents
Table Of Contents ................................................................ III
Tables ................................................................................ VII
Figures ................................................................................ IX
About This Manual ................................................................ XI
1. Introduction ..................................................................... 1
1.1 Product Overview ................................................................................................................................... 1
1.1.1 molbloc Flow Elements ........................................................................................................................... 1
1.1.1.1 molbloc-L Flow Element ......................................................................................................................... 1
1.1.1.2 molbloc-S Flow Element ........................................................................................................................ 2
1.2 Specifications ......................................................................................................................................... 2
1.2.1 General Specifications ............................................................................................................................ 2
1.2.2 Reference Pressure Transducer (RPT) Specifications .......................................................................... 3
1.2.2.1 Upstream and Downstream RPT s .......................................................................................................... 3
1.2.2.2 Differential RPT (Microrange Option) ..................................................................................................... 3
1.2.3 Temperature Measurement Speci fi cations ............................................................................................. 4
1.2.4 Flow Measurement Specifications .......................................................................................................... 4
1.2.4.1 molbloc-L Flow Measurement Spec i fications, Model Ranges 1E1-L t hru 3E 4-L .................................... 4
1.2.4.1.1 molbloc-L FLOW MEASUREMENT SPECIFICATIONS, MICRORANGE OPTION ............................ 5
1.2.4.1.2 molbloc-L Pressure Dependent Cali bration Types .............................................................................. 6
1.2.4.1.3 molbloc-L Ranges with Low Pressure Calibrati ons ............................................................................. 7
1.2.4.1.4 molbloc-L Ranges with High Press ure Cali brations ............................................................................ 8
1.2.4.1.5 molbloc-L DIMENSI ONS .................................................................................................................... 9
1.2.4.2 molbloc-S ............................................................................................................................................. 10
1.2.4.2.1 molbloc-S Pressure Dependent Calibration Types ........................................................................... 10
1.2.4.2.2 molbloc-S Ranges ............................................................................................................................ 11
1.2.4.2.3 molbloc-S Dimens i ons ..................................................................................................................... 22
1.2.5 Front and Rear Panels ........................................................................................................................... 24
1.2.5.1 Front Panel .......................................................................................................................................... 24
1.2.5.2 Rear Panel ........................................................................................................................................... 24
2. Installation ..................................................................... 25
2.1 UNPACKING AND INSPECTION .......................................................................................................... 25
2.1.1 Removing From Packaging ................................................................................................................... 25
2.1.2 Inspecting Contents ............................................................................................................................... 25
2.2 Site Requirements ................................................................................................................................ 25
2.3 Initial setup ........................................................................................................................................... 26
2.3.1 Preparing for Operation ......................................................................................................................... 26
2.3.2 Power Connection ................................................................................................................................. 26
2.3.3 molbox RFM to molbloc Connection .................................................................................................... 27
2.3.4 GAS Supply And Flowpath Connections .............................................................................................. 27
2.3.5 Vacuum Supply (molbloc-S only) .......................................................................................................... 28
2.3.6 Communications Connections.............................................................................................................. 28
2.4 Power UP and Verification ................................................................................................................... 29
2.4.1 Power UP ................................................................................................................................................ 29
2.4.2 Check Proper Pressure Measurem en t Op er ati o n ................................................................................ 29
2.4.3 Check Proper Temperature Measurem ent O peration .......................................................................... 29
2.4.4 Leak Check ............................................................................................................................................. 30
2.4.5 Check/Set Security Level ....................................................................................................................... 30
2.5 Additional Precautions to Take Before Making Flow Measurements .............................................. 30
2.6 Short Term Storage .............................................................................................................................. 31
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molbox™ RFM™ OPERATION AND MAINTENANCE MANUAL
3. Operation ....................................................................... 33
3.1 General Operating Principles .............................................................................................................. 33
3.1.1 molbloc-L and molbloc-S operation ..................................................................................................... 33
3.1.2 molbloc-S BPR Limits............................................................................................................................ 33
3.1.3 Flow Ready/Not Ready Indication ......................................................................................................... 34
3.1.3.1 molbloc-L Operation ............................................................................................................................. 35
3.1.3.2 molbloc-S Operation ............................................................................................................................ 35
3.1.4 Soft [On/Off] Key .................................................................................................................................... 35
3.1.5 Microrange option (Optional) ................................................................................................................ 36
3.1.6 Reference pressure transducer (RPT) overpressure ........................................................................... 37
3.1.6.1 Upstream and Downstream Abs ol ut e RP T S ........................................................................................ 37
3.1.6.2 Differential RPT, Microrange Opt i on ..................................................................................................... 37
3.2 Main Run Screen .................................................................................................................................. 37
3.2.1 molbloc-L Operation .............................................................................................................................. 38
3.2.2 molbloc-S Operation .............................................................................................................................. 39
3.3 Manual Operation ................................................................................................................................. 40
3.3.1 Keypad Layout and Protocol ................................................................................................................. 40
3.3.2 Sounds.................................................................................................................................................... 41
3.3.3 Soft [On/Off] Key .................................................................................................................................... 41
3.3.4 Direct Function Keys Summary ............................................................................................................ 41
3.4 Direct Function Keys ............................................................................................................................ 42
3.4.1 [K] ............................................................................................................................................................ 42
3.4.2 [GAS] ....................................................................................................................................................... 44
3.4.2.1 molbloc-L Operation ............................................................................................................................. 45
3.4.2.2 molbloc-S Operation ............................................................................................................................ 46
3.4.3 [UNIT] ...................................................................................................................................................... 48
3.4.3.1 Mass Flow vs. Volume Flow ................................................................................................................. 49
3.4.3.2 Volumetrically B ased Mass Flow Units ................................................................................................. 50
3.4.3.3 Volumetrically Based Mass Flow Units at Various Reference Temperatures (UXXX) ........................... 51
3.4.3.4 Volume Flow Units (vlm) ...................................................................................................................... 51
3.4.3.5 Customizing FLOW Units Available Under The UNIT Function ............................................................ 52
3.4.4 [TARE] ..................................................................................................................................................... 53
3.4.4.1 <1Tare> ............................................................................................................................................... 54
3.4.4.1.1 molbloc-L OPERATION ................................................................................................................... 54
3.4.4.1.2 molbloc-S Operation ........................................................................................................................ 57
3.4.4.2 <2Purge> ............................................................................................................................................. 58
3.4.4.3 <3Leak Check> .................................................................................................................................... 60
3.4.4.3.1 Leak Check molbox .......................................................................................................................... 61
3.4.4.3.2 Leak Check System ......................................................................................................................... 63
3.4.4.4 <4AutoZ> ............................................................................................................................................. 67
3.4.4.4.1 Edit AutoZ ........................................................................................................................................ 69
3.4.4.4.2 Run AutoZ ........................................................................................................................................ 70
3.4.4.5 <5BPR> (molbloc-S Operati on onl y) .................................................................................................... 72
3.4.5 [P&T] (Pressure and Temperature) ....................................................................................................... 73
3.4.6 [DISPLAY] ............................................................................................................................................... 75
3.4.6.1 <1Rate> ............................................................................................................................................... 76
3.4.6.2 <2AVG> (AVERAGE) ........................................................................................................................... 77
3.4.6.3 <3 Hi/Lo> ............................................................................................................................................. 78
3.4.6.4 <4TOTAL> (TOTALIZER) .................................................................................................................... 78
3.4.6.5 <5UNIT> .............................................................................................................................................. 80
3.4.6.6 <6DEV> ............................................................................................................................................... 81
3.4.6.7 <7FREEZE>......................................................................................................................................... 82
3.4.6.8 <8CLEAN> ........................................................................................................................................... 82
3.4.7 [MICRO] (Optional) ................................................................................................................................. 83
3.4.8 [molbloc] ................................................................................................................................................. 84
3.4.8.1 molbloc-L and molbloc-S size and Range Designations ....................................................................... 85
3.4.9 [RES] ....................................................................................................................................................... 86
3.5 [SETUP] ................................................................................................................................................. 86
3.5.1 <1FLOWU> ............................................................................................................................................. 87
3.5.2 <2PRESU> .............................................................................................................................................. 87
3.5.3 <3TEMPU> .............................................................................................................................................. 88
3.5.4 <4molbloc> ............................................................................................................................................. 88
3.5.5 <5stab> ................................................................................................................................................... 89
3.5.6 <6ADJ> .................................................................................................................................................... 90
© 2010 Fluke Calibration Page IV
TABLE OF CONTENTS
3.6 [SPECIAL] ............................................................................................................................................. 91
3.6.1 <1reset> .................................................................................................................................................. 92
3.6.1.1 <1sets> ................................................................................................................................................ 92
3.6.1.2 <2units> ............................................................................................................................................... 93
3.6.1.3 <3com> ................................................................................................................................................ 93
3.6.1.4 <4cal> .................................................................................................................................................. 93
3.6.1.5 <5all> ................................................................................................................................................... 94
3.6.2 <2level> ................................................................................................................................................... 94
3.6.2.1 Security Levels ..................................................................................................................................... 95
3.6.3 <3UL> ...................................................................................................................................................... 98
3.6.3.1 Upper Limit Alarm and S equence......................................................................................................... 99
3.6.4 <4cal>...................................................................................................................................................... 99
3.6.5 <5prefs> .................................................................................................................................................. 99
3.6.5.1 <1ScrSVR> .........................................................................................................................................100
3.6.5.2 <2Sound> ...........................................................................................................................................100
3.6.5.3 <3Time> ..............................................................................................................................................100
3.6.5.4 <4ID> ..................................................................................................................................................101
3.6.5.5 <5log> .................................................................................................................................................102
3.6.6 <6remote> ..............................................................................................................................................102
3.6.6.1 COM1 and COM2 ...............................................................................................................................103
3.6.6.2 IEEE-488 ............................................................................................................................................103
3.6.6.3 RS232 Self-Test ..................................................................................................................................103
3.6.7 <7Micro> ................................................................................................................................................104
3.6.8 <8Head> .................................................................................................................................................105
3.6.9 <9BPR> ..................................................................................................................................................106
4. Remote Operation ......................................................... 111
4.1 Overview ............................................................................................................................................. 111
4.2 Interfacing ........................................................................................................................................... 111
4.2.1 RS232 Interface .....................................................................................................................................111
4.2.1.1 COM1 .................................................................................................................................................112
4.2.1.2 COM2 .................................................................................................................................................112
4.2.2 IEEE-488 (GPIB) ....................................................................................................................................113
4.3 Commands .......................................................................................................................................... 113
4.3.1 Command Syntax ..................................................................................................................................113
4.3.2 COMMAND summary ............................................................................................................................114
4.3.3 Error Messages .....................................................................................................................................116
4.3.4 Command Descriptions ........................................................................................................................117
4.3.4.1 IEEE Std. 488.2 Common and Status Commands ..............................................................................117
4.3.4.2 MOLBOX rfm commands ....................................................................................................................121
4.4 Status System ..................................................................................................................................... 147
4.4.1 Status Reporting System ......................................................................................................................147
4.4.1.1 Status Byte Register ...........................................................................................................................147
4.4.1.2 Standard Event Register .....................................................................................................................149
5. Maintenance, Adjustments And Calibration ..................... 151
5.1 Product Overview ............................................................................................................................... 151
5.2 Calibration of Reference Pressure Transducers (RPTs) ................................................................ 152
5.2.1 Principle.................................................................................................................................................152
5.2.1.1 PA and PM Coefficients ......................................................................................................................153
5.2.2 Equipment Required .............................................................................................................................153
5.2.2.1 upstream and downstream AB solute RPTs .........................................................................................153
5.2.2.2 Differential (microrange) RP T ..............................................................................................................154
5.2.3 Set-Up and Preparation ........................................................................................................................154
5.2.3.1 UPSTREAM AND DOWNSTREAm Absolute RPTS ...........................................................................154
5.2.3.2 MICRORANGE Differential RP T .........................................................................................................155
5.2.4 Viewing and editing RPT READINGS AND Calibration Information...................................................155
5.2.4.1 Viewing RPT outputs ...........................................................................................................................156
5.2.4.2 Viewing and Editing rpt PA, PM and Calibration dat e ..........................................................................158
5.2.5 RPT Calibration/Adjustment Procedure Without Using CALTOOL for RPTS Software ....................159
5.3 OHMIC Measurement System Verification ....................................................................................... 160
5.3.1 OHMIC Measurement S ystem Calibration /Adjustment Procedure .....................................................162
Page V © 2010 Fluke Calibration
molbox™ RFM™ OPERATION AND MAINTENANCE MANUAL
5.4 Reloading Embedded Software Into molbox RFM Flash Memory ................................................. 163
5.5 RELOADING MOLBLOC EEPROM FILE ............................................................................................ 163
5.6 Overhaul .............................................................................................................................................. 163
5.6.1 Internal View ..........................................................................................................................................164
5.6.1.1 Upstream absolute RPT ......................................................................................................................165
5.6.1.2 Downstream absolute RPT .................................................................................................................165
5.6.1.3 Differential mic rorange RPT (opt i onal ) ................................................................................................165
5.6.1.4 Display ................................................................................................................................................165
5.6.1.5 Power Supply ......................................................................................................................................165
5.6.1.6 Micro Board .........................................................................................................................................165
5.6.1.7 Valving Module....................................................................................................................................165
5.6.1.8 Main Board ..........................................................................................................................................166
5.6.1.9 Cooling fan ..........................................................................................................................................166
6. Troubleshooting ........................................................... 167
6.1 OVERVIEW .......................................................................................................................................... 167
7. Appendix ...................................................................... 173
7.1 CONVERSION OF NUMERICAL VALUES.......................................................................................... 173
7.1.1 PRESSURE ............................................................................................................................................173
7.1.2 Temperature ..........................................................................................................................................173
7.1.3 Flow .......................................................................................................................................................174
7.2 Limited Warranty and Limitation of Liability .................................................................................... 177
8. Glossary ...................................................................... 179
© 2010 Fluke Calibration Page VI
Tables
Table 1. molbloc-L Pressure Dependent Calibration Types ......................................................................... 6
Table 2. molbloc-L Ranges with Low Pressure and Downstream Calibrations ............................................ 7
Table 3. molbloc-L Ranges with High Pressure Calibrations ....................................................................... 8
Table 4: molbloc-S Calibration Types ......................................................................................................... 11
Table 5: N2. molbloc-S Flow in Nitrogen at Various molbloc Upstream Pressures ................................... 12
Table 6: Ar. molbloc-S Flow in Argon at Various molbloc Upstream Pressures ........................................ 12
Table 7: He. molbloc-S Flow in Helium at Various molbloc Upstream Pressures ..................................... 13
Table 8: SF6. molbloc-S Flow in Sulfur Hexafluoride at Various molbloc Upstream Pressures ................ 13
Table 9: Xe. molbloc-S Flow in Xenon at Various molbloc Upstream Pressures ...................................... 14
Table 10: C4H10. molbloc-S Flow in Butane at Various molbloc Upstream Pressures ............................. 14
Table 11: C2H6. molbloc-S Flow in Ethane at Various molbloc Upstream Pressures ............................... 15
Table 12: C2H4. molbloc-S Flow in Ethylene at Various molbloc Upstream Pressures ............................ 15
Table 13: H2. molbloc-S Flow in Hydrogen at Various molbloc Upstream Pressures ............................... 16
Table 14: CH4. molbloc-S Flow in Methane at Various molbloc Upstream Pressures .............................. 16
Table 15: C3H8. molbloc-S Flow in Propane at Various molbloc Upstream Pressures ............................ 17
Table 16: CF4. molbloc-S Flow in Carbon Tetrafluoride at Various molbloc Upstream Pressures ........... 17
Table 17: C2F6. molbloc-S Flow in Hexafluoroethene at Various molbloc Upstream Pressures .............. 18
Table 18: CHF3. molbloc-S Flow in Trifluoromethane at Various molbloc Upstream Pressures .............. 18
Table 19: Air. molbloc-S Flow in Air at Various molbloc Upstream Pressures .......................................... 19
Table 20: CO2. molbloc-S Flow in Carbon Dioxide at Various molbloc Upstream Pressures ................... 19
Table 21: CO. molbloc-S Flow in Carbon Monoxide at Various molbloc Upstream Pressures ................. 20
Table 22: N2O. molbloc-S Flow in Nitrous Oxide at Various molbloc Upstream Pressures ...................... 20
Table 23: C4F8. molbloc-S Flow in Octafluorocyclobutane1 at Various molbloc Upstream Pressures ..... 21
Table 24: O2. molbloc-S Flow in Oxygen at Various molbloc Upstream Pressures .................................. 21
Table 25. molbox RFM Parts List ............................................................................................................... 25
Table 26: Minimum molbloc-S Critical Flow (slm) in Nitrogen at Various
molbloc-S Downstream Pressures .......................................................................................... 34
Table 27. Summary of molbox RFM Direct Function Key Operations ....................................................... 42
Table 28. Available molbloc-L Gases ......................................................................................................... 45
Table 29. Available Flow Units ................................................................................................................... 52
Table 30. Flow Units and Corresponding Total Mass or Volume Units ...................................................... 80
Table 31. molbloc-L Size and Nominal Range Designations ..................................................................... 85
Table 32. molbloc-S Size Designation and Pressure to Flow Conversion Ratio (KF) ................................. 86
Table 33. Pressure Units of Measure Available ......................................................................................... 88
Table 34. Security Levels - Functions NOT Executed Per Function/Level ................................................ 96
Table 35. Security Levels - Functions NOT Executed Per Function/Level (Continued) ............................. 97
Table 36. COM1 and COM2 Available Settings ....................................................................................... 103
Table 37. COM1 DB-9F Pin Designation ................................................................................................. 112
Table 38. COM2 DB-9M Pin Designation ................................................................................................. 113
Table 39. Command Summary ................................................................................................................ 114
Table 40. Error Messages ........................................................................................................................ 116
Table 41. Status Byte Register ................................................................................................................. 147
Table 42. Standard Event Register .......................................................................................................... 149
Table 43. Troubleshooting Checklist ........................................................................................................ 167
Page VII © 2010 Fluke Calibration
ABOUT THIS MANUAL
Table 44. Pressure Unit Conversions ...................................................................................................... 173
Table 45. Temperature Unit Conversion .................................................................................................. 173
Table 46. Conversions From kg/s To sccm At 0 °C For Various Gases .................................................. 174
Table 47. Conversions From sccm At 0 °C To Other Volumetrically Based Flow Units .......................... 174
Table 48. Conversions From Volumetrically Based Flow Units At 0 °C To Corresponding Units
At Another Temperature (uxxx) ............................................................................................. 175
Table 49. Conversions From kg/s To mole/s For Various Gases ............................................................ 175
Table 50. Conversion From mole/s To pccm ........................................................................................... 176
Table 51. Conversion From sccm At 0 °C to Volume Flow Units At Another Pressure
And Temperature ................................................................................................................... 176
Table 52. Fluke Calibration Authorized Service Providers ....................................................................... 178
© 2010 Fluke Calibration Page VIII
Figures
Figure 1. molbloc-L Upstream End Flange with Integrated Filter ................................................................. 2
Figure 2. molbox RFM Front Panel ............................................................................................................ 24
Figure 3. molbox RFM Rear Panel ............................................................................................................. 24
Figure 4. molbox RFM Internal Pneumatic Schematic – ............................................................................ 36
Figure 5. Keypad Layout ............................................................................................................................ 40
Figure 6. molbox RFM Internal Pneumatic Schematic – TARING,
UPSTREAM molbloc-L OPERATION ...................................................................................... 55
Figure 7. molbox RFM Internal Pneumatic Schematic – TARING molbloc-S OPERATION ...................... 58
Figure 8. molbox RFM Internal Pneumatic Schematic – PURGING .......................................................... 59
Figure 9. molbox RFM Internal Pneumatic Schematic – LEAK CHECK molbox ....................................... 62
Figure 10. molbox RFM Internal Pneumatic Schematic – SYSTEM LEAK CHECK –
CHECKING OFFSET AND STABILITY molbloc-L operation .................................................. 64
Figure 11. molbox RFM Internal Pneumatic Schematic – SYSTEM LEAK CHECK –
CHECKING OFFSET AND STABILITY molbloc-S operation .................................................. 66
Figure 12. molbox RFM Internal Pneumatic Schematic – molbloc-S OPERATION, BPR ON ................ 107
Figure 13. molbox RFM Internal Pneumatic Schematic – molbloc-S OPERATION, BPR OFF ............... 107
Figure 14. Status Byte Register ............................................................................................................... 148
Figure 15. molbox RFM Internal Pneumatic Schematic – RUN UPSTREAM OR DOWNSTREAM
ABSOLUTE RPT CALIBRATION .......................................................................................... 157
Figure 16. molbox RFM Internal Pneumatic Schematic – RUN MICRORANGE DIFFERENTIAL
RPT CALIBRATION............................................................................................................... 158
Figure 17. molbox RFM Internal View ...................................................................................................... 164
Figure 18. molbox RFM Valving Assembly Schematic ............................................................................ 166
Page IX © 2010 Fluke Calibration
ABOUT THIS MANUAL
Notes
© 2010 Fluke Calibration Page X
About This Manual
This manual provides the user with the infor mation necessary to operate a molbox RFM, Referenc e Flow
Monitor. It also includes a great deal of additional information provided to help you optimize molbox RFM use
and take full advantage of its many features and functions.
Before using the m anual, tak e a m om ent to f am iliarize yourself with the Table of Contents str ucture: All f irst
time molbox RFM user s should read Section 2. Section 3 provides a comprehensive description of gener al
molbox RFM operating principles. Section 4 is for remote operation from an ex ternal computer. Section 5
provides maintenance and calibration information. Section 6 is a quick troubleshooting guide. Use it to
troubleshoot unexpected molbox RFM behavior based on the symptoms of that behavior.
Certain words and expres s ions have s pecif ic meaning as they pertain to molbox RFM. Section 8 is useful as
a quick reference for exact definition of specific words and expressions as they are used in this manual.
Note
For those of you who “don’t read manuals”, go directly to section 2.3, initial setup,
to set up your molbox RFM. Then go to section 2.4, power up and verification.
This will get you running quickly with minimal risk of causing damage to yourself
or your molbox RFM. THEN… when you have questions or start to wonder about
all the great features you might be missing, get into the manual!
Manual Conventions
Caution
“Caution” is used in throughout the manual to identify conditions or actions that
could cause harm to the molbox RFM or to the devices that are connected to the
molbox RFM.
Warning
“Warning” is used in throughout the manual to identify actions that could pose a
hazard to the user of the molbox RFM.
Note
“Note” is used throughout the manual to identify operating and applications advice
[ ] Indicates direct function keys (e.g., [RANGE]).
< > Indicates molbox1+ screen displays (e.g., <1yes>).
and additional explanations.
Page XI © 2010 Fluke Cali brat i on
ABOUT THIS MANUAL
Notes
© 2010 Fluke Calibration Page XII
1. Introduction
1.1 Product Overview
molbox RFM is a support unit for making low mass flow measurements using molbloc mass
flow elements. molbox RFM reads calibration data off the molbloc EEPROM and measures molbloc
upstream and downstream pressure using built-in high accuracy Reference Pressure
Transducers (RPTs). An ohmic measurement system reads the resistance of the molbloc platinum
resistance thermometers from which molbloc temperature is calculated. Using the molbloc calibration
data, pressures, temperature and gas properties stored in memory, the flow rate of the gas flowing
through the molbloc is calculated. For molbloc-L laminar flow element model ranges 1E1-L to 3E4-L a
microrange option is available to increa se resoluti on and accuracy be low 10 % FS of the flow ra nge. For
the molbloc-L model range 1E5-L the microrange option is required to achieve the stated uncertainty due
to the very low differential pressure of this range. The microrange option has no function in relation to
the molbloc-S sonic flow elements.
Internal molbox RFM valving supports on-boar d PRESSURE TRANSDUCER TARING , LEAK TESTING
and SELF PROTECTION functions as well as a gas purge routine.
molbox RFM provides a loc al user interface via a fr ont panel key pad and display and includes advanced
on-board functions. Remote communication capability is supported with RS232 and IEEE-488 interfaces.
molbox RFM is intended for applications in which a highly compact presentation, high range ability and
lower cost are the prim ary considerations. A second m odel, m olbox 1+, is available for applications where
higher accuracy is the most important requirement.
1.1.1 molbloc Flow Elements
Two different types of molblocs may be used with molbox RFM; molbloc-L (laminar) and
molbloc-S (sonic). The molbox RFM version 1.20 or later maintains support for older
molblocs but also supports operation with new or upgraded molblocs that have the updated
data structure to take advantage of molbox1+ features.
1.1.1.1 molbloc-L Flow Eleme nt
molbloc-L is the original molbloc laminar flow element. molbloc-L covers the
lower portion of the molbloc/molbox system flow range. The key molbloc-L
measurement is the differential pressure across the element, which is roughly
proportional to the m ass flow rate through it. molbloc -L elements are calibrated
to be used at an absolute pressure that remains nearly constant, while the
differential pressure varies with flow rate. Different operating pressure options
and their effect on molbloc flow range are described in Section 1.2.4.1.2.
Page 1 © 2010 Fluke Cal i brat i on
molbox™ RFM™ OPERATION AND MAINTENANCE MANUAL
In addition to the new data structure and modelization methods that became
available for molblocs with the introduction of molbox1+, all molbloc-L elements
of range 1E1-L to 3E4-L produced or upgraded af ter the r elease of m olbox1+ are
equipped standard with an upstream ¼” VCR flange, or f lowpath connection, that
has an integrated sintered metal filter. T his filter is intended to be a last defense
against particulate contamination of the molbloc-L internal flowpath which can
affect molbloc-L m easurem ents. Every eff ort should still be m ade to supply clean
dry gas to the molbloc to ensure its measurement performance and long-term
stability. molblocs that have the integrated upstream filter are recognizable by the
visible filter element as shown below.
Figure 1. molbloc-L Upstream End Flange with Integrated Filter
New molbloc-L elements produced with molbox1+ calibration data structure,
premium calibration options, and integrated filter hardware can be identified by
having a serial number of 6000 or higher. Most older molbloc-L elements are
eligible for upgrade to this hardware/version by Fluke Calibration.
1.1.1.2 molbloc-S Flow Eleme nt
molbloc-S elements us e critical (s onic) f low venturi nozzle technology to measure
flows, which overlap with the higher molbloc-L ranges and ex tend the high end of
the molbloc/molbox RFM system flow range. The mass flow rate through a
molbloc-S element is roughly proportional to the upstream absolute pressure
when the flow is “choked”, so the molbloc-S operating pres sure can vary widely
as the mass flow rate is changed throughout the flow range. The limits of
molbloc-S operating pressure and flow ranges are defined by the molbloc-S
calibration type, described in Section 1.2.4.2.2.
New calibration data structure and premium calibration options for molbloc-S
were also introduced along with molbox1+. molbloc-S elements produced with
this support will have serial num ber of 4000 or higher. O lder molbloc-S elem ents
are eligible for upgrade to this version format by Fluke Calibration.
1.2 Specifications
1.2.1 General Specifications
Power Requirements
Fuse
Operating Temperature Range
Storage Temperature Range
Vibration
Weight
Dimensions
© 2010 Fluke Calibration Page 2
85 to 264 VAC, 47 to 440 Hz, 18 VA m ax. c onsumption
1A/250V, slow blow, 5x20mm, NSN: 5920008930491
15 to 35 °C
-20 to 70 °C
Meets MIL-T-28800D
2.55 kg (5.6 lb) max.
8 cm H x 22.5 cm W x 20 cm D
(3.1 in. x 8.9 in. x 7.9 in.) approx.
1. INTRODUCTION
Microprocessor
Communication Ports
Reference Pressure Transducers
(RPTs)
Ohmic Measurement System
Gases Supported
Pressure Connections
Pressure Limits
Flow Ranges
CE Conformance
Motorola 68302, 16 MHz
RS232 (COM1), RS232 (COM2), IEEE-488
Standard: 2 x 600 kPa (87 psia) calibrated range piezores i s tive silicon
Microrange option: 12.5 kPa (1.8 psi d) pi ezores i stive silicon
Resolution: 0.004 Ω
Accuracy: ± 0.04 Ω
Accuracy of 100 and 110 Ω ref erence resistors: ± 0.01 %
Stability of 100 and 110 Ω reference resistors: ± 0.005 % per three years
molbloc-L and molbloc -S
Nitrogen (N2), dry Air, humid Air (molbloc-S only) , Argon (Ar), B utane
(Butn), Carbon Monoxide (CO), Helium (He), Oxygen (O2), Carbon
Dioxide (CO2), Carbon Tetrafluoride (CF4), Octofluorocyclobutane
(C4F8), Ethane (C2H6), Ethylene (C2H4), Fluoroform (CHF3),
Hexafluoroethane (C2F6), Hydrogen (H2), Methane (CH4), Nitrous
Oxide (N2O), Propane (C3H8), Sulfur Hexafluoride (SF6), Xenon (Xe)
Quick connectors equivalent to Swagelok QM Series (-QM2-B200)
Maximum working pressure 600 kPa absolute (87 psi a)
Maximum pressure without damage 800 kPa absolute (115 psia)
NOTE: The microrange option includes a 12. 5 kPa (1.8 psi) differenti al
RPT which may be damaged by differenti al pressure greater than 100
kPa (15 psi).
See Sections 1.2.4. 1. 3, 1.2.4.1.4and 1.2.4.2. 1
Available. Must be specif i ed.
1.2.2 Reference Pressure Transducer (RPT) Specifications
1.2.2.1 Upstream and Downstream RPTs
Piezoresistive silicon
Type
Range
Resolution
Repeatability
Accuracy
1.2.2.2 Differential RPT (Microrange Option)
Range
Resolution
Repeatability
Accuracy
0 to 600 kPa absolute (0 to 87 psia)
6.0 Pa (0.0009 psi)
± 0.01 % FS
Absolute measurements: ± 0.06 % FS f or one year
Differential measurements: ± (20 Pa + 0.05 % ∆Ρ). T ari ng sequence eliminates zero
error on measurement of dif ference between the two RPTs.
Piezoresistive silicon
Type
0 to 12.5 kPa differenti al (0 t o 1.8 psid)
0.14 Pa (0.00002 psi)
± 0.01 % FS
± (0.14% of reading + 0.01% F.S .) for one year.
Taring sequence eliminates zero error.
Page 3 © 2010 Fluke Calibration
molbox™ RFM™ OPERATION AND MAINTENANCE MANUAL
1.2.3 Temperature Measurement Specifications
Specifications are for m olbloc mounted Platinum Resistance T hermom eters (PRT ) combined
with molbox RFM resistance measurement system and temperature calculation.
Range
Accuracy
Resolution
0 to 40 °C
± 0.05 °C
0.01 °C
The molbox RFM internal res istance measurement system is autom atically calibrated using
reference 100 and 110 Ω (± 0.01 %) resistors (see Section 5.3).
1.2.4 Flow Measurement Specif i cations
molbox RFM meas ures the f low through molbloc flow elements. Ther e are two different types
of molblocs, molbloc-L (laminar) (see Section 1.1.1.1) and molbloc-S (sonic) (see Section
1.1.1.2). Flow measurement specifications, calibration types, ranges and dimensions are
detailed separately for each molbloc type in Section 1.2.4.1 and 1.2.4.2.
All flow measurem ent uncertainties are valid only for measurem ents in a gas for which the
molbloc is calibrated, and within the range of pressures for which the calibration is specified.
1.2.4.1 molbloc-L Flow Measurement Specifications, Model Ranges 1E1-L thru 3E4-L
The flow range, useable operating pressure and absolute and differential
pressure associated with molbloc -L operation depend on the molbloc used and its
pressure-dependent calibration options (s ee Section 1.2.4.1.2). Use of mobloc-L
model range 1E5-L is only recomm ended for us e with the mic rorange option (s ee
Section 1.2.4.1.1).
Measurement Update Rate
Range
Resolution
Linearity
Repeatability
Precision
Stability
(1 year)
Measurement Uncertainty
(1 year, N2 and any molbox RFM
supported gas for which the molbl oc
1 Precision: Combined linearity, hysteresis, repeatability.
2 Stability: Maximum change in zero and span over specified time period for typical molbox RFM and molbloc used
under typical conditions. As stability can only be predicted, stability for a specific molbox RFM should be
established from experience.
3 Measurement Uncertainty: Maximum deviation of the molbox RFM flow indication from the true value of the flow
through the molbloc including precision, stability and Fluke calibration standard uncertainty. Measurement
uncertainty specifications for molblocs are valid only for gases with which the molbloc has been calibrated. All
molblocs are calibrated for N
maintained at all times for all gases on all molbloc designations. Check for availability before ordering.
in use is calibrated)
2. Calibrations with other gases are optional. Fluke calibration capability is not
1 second
0 to molbloc full s cale depending on gas and molbloc
pressure dependent calibration type
(see Section 1.2.4.1.2).
0.01 % FS
± 0.23 % of reading from 10 t o 100 % F S,
± 0.023 % FS under 10 % FS
± 0.1 of reading from 10 to 100 % F S,
± 0.01 % FS under 10 % FS
1
± 0.25 % of reading from 10 t o 100 % FS,
± 0.025 % FS under 10 % FS
2
± 0.15 % of reading from 10 t o 100 % F S,
± 0.015 % FS under 10 % FS
3
± 0.5 % of reading from 10 t o 100 % F S,
± 0.05 % FS under 10 % FS
© 2010 Fluke Calibration Page 4
1. INTRODUCTION
1.2.4.1.1 molbloc-L FLOW MEASUREMENT
SPECIFICATIONS, MICRORANGE OPTION
The microrange option (see Section 1.2.2.2) improves molbloc-L flow
measurement s pecifications below 10 % FS of the molbloc model ranges 1E1-L
thru 3E4-L, and is required to achieve the measurement specification of molbloc
model range 1E5-L. With the microrange option, the affected measurement
specifications become:
Molbloc-L (Ranges 1E1-L Thru 3E4-L)
Update Rate
Range
Resolution
Linearity
Repeatability
Precision
Stability
(1 year)
Measurement Uncertainty
molbloc-L (Ranges 1E5-L Only)
Update Rate
Range
Resolution
Linearity
Repeatability
Precision
Stability
(1 year)
Measurement Uncertainty
1 Precision: Combined linearity, hysteresis, repeatability.
2 Stability: Maximum change in zero and span over specified time period for typical molbox RFM and molbloc used
under typical conditions. As stability can only be predicted, stability for a specific molbox RFM should be
established from experience.
3 Measurement Uncertainty: Maximum deviation of the molbox RFM flow indication from the true value of the
flow through the molbloc including precision, stability and Fluke calibration standard uncertainty. Measurement
uncertainty specifications for molblocs are valid only for gases with which the molbloc has been calibrated. All
molblocs are calibrated for N
maintained at all times for all gases on all molbloc designations. Check for availability before ordering.
2. Calibrations with other gases are optional. Fluke calibration capability is not
1 second
0 to molbloc full s cale depending on gas and molbloc
pressure dependent calibration type (s ee molbloc-L tables)
0.01% FS, 0.001% FS under 10% FS
±0.23% of reading from 1 to 100% FS,
±0.0023% FS under 1% FS
±0.1% of reading from 1 to 100% FS,
±0.001% FS under 1% FS
1
±0.25% of reading from 1 to 100% FS,
±0.0025% FS under 1% FS
2
±0.15% of reading from 1 to 100% FS,
±0.0015% FS under 1% FS
3
±0.5% of reading from 1 to 100% FS,
±0.005% FS under 1% FS
1 second
0 to molbloc full scale depending on gas and molbloc
pressure dependent calibration type (s ee molbloc-L tables)
0.01% FS
± 0.25% of reading from 5 to 100% FS,
± 0.0125% FS under 5% FS
± 0.2% of reading from 5 t o 100% F S,
± 0.01% FS under 5% FS
1
± 0.32% of reading from 5 to 100% FS,
± 0.016% FS under 5% FS
2
± 0.2% of reading from 5 to 100% FS,
± 0.01% FS under 5% FS
3
± 0.5% of reading from 5 to 100% FS,
± 0.025% FS under 5% FS
Page 5 © 2010 Fluke Calibration
molbox™ RFM™ OPERATION AND MAINTENANCE MANUAL
PRESSURE AT MAX. FLOW
MOLBLOC
MOLBLOCS
1.2.4.1.2 molbloc-L Pressure Dependent Calibration Types
See your molbloc’s Calibration Report to determine the
calibration type of the molbloc you are using.
Different pressure dependent calibration options for molbloc-L elements determine
the range of operating pressures over which a molbloc can be used within its
mass flow measurement specifications. The calibration option also affects the
molbloc flow range and the differential pressure associated with the flow range.
Measurement uncertainty (accuracy) specifications for molbloc-L are valid only for
gases with which the molbloc has been calibrated. All m olbloc-L elements are
calibrated for N2. Calibrations with other gases are optional. Fluke calibration
capability is not maintained at all times for all gases on all molbloc designations.
Check for availability before ordering calibrations.
The molbloc-L pressure dependent calibration types are summarized in Table 1.
Table 1. molbloc-L Pressure Dependent Calibration Types
Note
CALIBRATION TYPE
(CALIBRATION NAME)
Low pressure
(LOP)
High pressure
(HIP)
Downstream
(DOWN)
OPERATING PRESSURE
200 to 325 kPa absolute
(29 to 48 psia)
upstream of molbloc
325 to 525 kPa absolute
(48 to 76 psia)
upstream of molbloc
Atmospheric pressure
downstream of m ol bl oc. 85 to
105 kPa (12 to15 psia).
NOMINAL DIFFERENTIAL
1E5
5 kPa
(.725 psi)
Not available 50 kPa
12.5 kPa
(1.8 psi)
ALL OTHER
50 kPa
(7.5 psi)
(7.5 psi)
80 kPa (12 psi)
Note
Differential pressure values are nominal and may vary by up to
15 % with the actual molbloc used.
© 2010 Fluke Calibration Page 6
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