CalTool™ for molbloc™ A PC Based Calibration Utility For molbloc
Contents
1. ASSURE GOOD MEASUREMENTS 3 2 MANUAL CREATION OF A CALIBRATION DATA FILE scssssssssessessssssssssssssssatssesatescesceseesessessessees 3 3 CREATING AND USING molbloc RESTORE FILES s ss ssssssssssesssssessnsssssesenssssatsntsaeeseesesaeeseessesnes MAIN MENU 65 2222 2 15 JOCALIBRATION Dati ducha tee 15 CALIBRATION TEST inicie eed 15 4 1 1 1 CALIBRATION TEST VERIFICATION TEST RUN SCREEN 17 411 2 00 ttt ttt ttt ttt ttt tts 18 412 VERIFICATION a S 19 4 1 3 CALCULATION 4104 e 13 2 lt 42 1 INTERFACE 4229 uiui ti uud ake i tend PLA D 43 4 3 1 CREATE 432 43 3 4 3 4 43 5 VIEW 44 TOOLS MENU 44 1 REMOVE GAS 44 2 RESTORE molbloc 44 3 CREATE RESTORE FILE 444 VIEW molbloc CALIBRATION Pagei 1999 DH Instruments Inc for molbloc User s Manual 4 4 5 CHANGE molbloc CALIBRATION 1 4 42 1 12040 000 00 40000 0 04 00004400 00 00002. 28 45 WINDOW MENU aet a UR D A Vue 28 5 CALTOOL FILE TYPES AND CHARACTERISTICS 29 53 E Ea aeaeo 29 52 29 53 RESULT FILE 30 54 molbloc RESTORE adii assi ta 31 6 molbloc NOMINAL FLOW RANGE SIZE DESIGNATIONS AND ACTUAL PRESSURE RANGES WITH VARIOUS GASES 22050 33 6 1 molbloc SIZE AND RANGE DESIGNATIONS s ssssssessessssssesssesssssnesssssnessnessessneesessneesessaeenseeneenseene 33 6 2 molbloc PRESSURE DEPENDENT CALIBRATION TYPEG s ssssssssssssessssssesssssnessessessseesessneensesass 34 f GLOSSARY inco oes tinc En Apad estu tenia T beds 37 1999 DH Instruments Inc Page ii CalTool for molbloc User s Manual FIGURES Figure 1 molbloc molbox Mass Flow qm 2 e 2 Figure 2 Calibration Test Verification Test Run Screen 0 17 Figure 3 Calculation Activation 20 Figure 4 Interface Setup eene nennen snnt 22 Figure 5 Interface Setup Window RS232 Settings nennen 22 Figure 6 Test Data Entry 24 6 26 Table 1 Tools Available on the Run Test 18 Table 2 molbloc Size and Nomina
3. Carbon Dioxide Carbon Monoxide Oxygen Nitrous Oxide A bold value indicates that the maximum flow is limited by the maximum Reynolds number value of 1 200 which is reached before the normal differential pressure range is reached In that case the second value gives the minimum flow for which measurement uncertainty accuracy is a of the measured value With the microrange option this value is divided by 10 see molbloc Flow Measurement Specifications in the molbox Operation and Maintenance Manual Where there is no value in the table this indicates that the maximum Reynolds number is reached before the differential pressures reaches 5 kPa therefore calibration with that gas is not useful 1999 DH Instruments Inc Page 36 CalTool for molbloc User s Manual 7 GLOSSARY Reading Error The disagreement of the DUT and the reference expressed as a of the reference reading DUT reference reference 100 Absolute Beta G re Calibration Gas Test Gas Calibration Test Downstream As in absolute pressure Pressure expressed relative to vacuum One of the molbloc calibration coefficients manipulated by CalTool for molbloc The slope of the variation of C with Reynolds number One of the molbloc calibration coefficients manipulated by CalTool for molbloc Geometry of the molbloc flow path and Reynolds number dependence The gas
4. molbloc molbloc Difference Ener Flow Flow Re Figure 6 Test Data Entry Form EDIT Use Data Edit to edit an existing data file dat The operation of Edit is identical to Create except that an existing data file is selected and loaded into the editor instead of starting from a blank form see Section 4 3 1 1999 DH Instruments Inc Page 24 CalTool for molbloc User s Manual BHI 433 PLOT Plot allows the CalTool of reading error plot for an existing data dat or result res file to be viewed To view a plot select Data Plot Then click lt Result File gt or lt Data File gt to specify the type of file to be plotted The lt Select File gt window is presented Select the desired file and click lt Open gt The plot can be printed using Data Print or the lt Print gt toolbar option see Section 4 3 4 96 of reading error is calculated following test reference reference 100 Plots of result files res include both the as received and as left data of reading error plote 434 PRINT Print allows a data file dat result file res plot or other text displays to be printed to the selected Windows printer To print select Data Print Then click the desired item to be printed from the drop down list If Result File or Data File is selected the file to print must be selected from a Select File windo
5. The test gas list available in CalTool is the complete list of molbox supported gases at the time the version of CalTool was released If your version of CalTool does not include a test gas that is available on the molbox you are using or vice versa visit www dhinstruments com to download a newer version of CalTool and or molbox embedded software 4 3 DATA MENU The Data menu offers various tools to work with CalTool data files The Data menu includes the following selections Create Edit Plot Print and View 431 CREATE Create is used to create a data file dat manually This option is useful to create a data file from data taken at a time or place when CalTool with remote communications to a test molbox were not available To create a data file dat manually select Data Create The Test Data Entry window is presented Fill out the form The Test Gas may be selected from the Gas drop down list The molbloc serial number must be correct as it will be verified and must match the connected molbloc when the data file is used with the Calculate function see Section 4 1 3 In the test data grid the reference flow molbloc flow and molbloc Reynolds number must be entered for a minimum of three points CalTool automatically calculates the difference and 96 reading error O should not be included as a reference flow point as this results in an invalid reading error Select Save to save the dat
6. to cause the new as left calibration coefficients for the test gas to be written to the molbloc CalTool will again verify the actual molbloc information with the information stored in the data file If these do not match the calibration cannot be activated If they do match the new calibration coefficients are written to the molbloc and the lt Save Result File As gt window is presented Only the calibration coefficients relating to the gas specified in the dat file are adjusted no other molbloc information is adjusted lt Calculate gt is available to cause CalTool to recalculate for example if an error occurred during the original calculation Calculation Activation E SOFTWARESCTMLBLOC DATA molbloc 217 2 dat Reference Model molboxt Ver 4 025 Test Pressure 274 kPa Identification Station H6 Flow Unit Serial Number molbox 430 molbloc 723 82 Header Serial Number 7 Model molbox1 Ver 4 02 Nominal Range f 00 seem Serial Number 407 m s Received As Left Cg 14 Cg 1 059047E 13 Beta 4 013283 05 Beta 3 614003 04 As Left As Left Reference molbloc molbloc As Left Flow Flow Re Difference Error Uc Difference SIG 1 2 3 4 5 Calculate Activate Calibration Figure 3 Calculation Activation Screen 414 EXIT Exit is used to close the CalT
7. desired selections on the RS232 setup form Default molbox settings are 2400 E 7 1 If lt IEEE 488 gt is selected the IEEE 488 address of the molbox must be specified in the field provided The IEEE 488 Card in the PC must be selected in drop down list in the lt IEEE 488 gt selection box at the bottom of the form The IEEE 488 card must be set up with default addresses and 32 bit drivers for a Windows based 32 bit operating systems After a device interface is modified click Accept so the value is updated in memory If Accept is not clicked the interface value will not be saved Communications Test causes CalTool to send a test command to the The detection status will display after the command is sent Select Close to exit the interface setup form Page 21 1999 DH Instruments Inc CalTool for molbloc User s Manual Interface Setup Test molbox Remote Interface 2400 E 7 1 IEEE 488 Card Figure 4 Interface Setup Window Figure 5 Interface Setup Window RS232 Settings 1999 DH Instruments Inc Page 22 CalTool for molbloc User s Manual 422 TEST GAS Test Gas specifies the gas species for which CalTool Calibration and Verification Tests are run To select the test gas select Setup Test Gas A drop down menu of the test gases available appears The current test gas is checked To change test gas click the desired gas
8. e the molbloc serial number e Restore label to identify the file as a restore file e brs automatic file extension of a molbloc restore file The default path for a molbloc restore file is CalTool for molbloc Restore brs If a new file location is selected while saving all restore brs files will be saved to the selected path by default until another path selection is made 1999 DH Instruments Inc Page 32 CalTool for molbloc User s Manual 6 molbloc NOMINAL FLOW RANGE SIZE DESIGNATIONS AND ACTUAL PRESSURE RANGES WITH VARIOUS GASES 6 1 molbloc SIZE AND RANGE DESIGNATIONS Until mid 1999 molblocs were always identified by Range The Range is the molbloc s nominal full scale flow in Nitrogen N2 at an operating pressure of 250 kPa Actual molbloc ranges change with operating pressure and calibration gas see the molbox Operation and Maintenance Manual Flow Measurement Specifications Since mid 1999 molblocs have been designated by size with a sizing code On molbloc EPROM s the molbloc is still identified by its nominal range rather than by its size therefore CalTool identifies molblocs by their nominal ranges molbloc size and range designation correspondence are given in Table 2 Page 33 1999 DH Instruments Inc CalTool for molbloc User s Manual Table 2 molbloc Size and Nominal Range Designations molbloc NOMINAL molbloc SIZE
9. e Use a molbox that is known to have a valid calibration If the molbox pressure transducer s measurement uncertainty is not in tolerance the molbloc calibration will not be valid e Check that the molbox K is set to zero Page 11 1999 DH Instruments Inc CalTool for molbloc User s Manual e Check that the SETUP lt 6adj gt Adder 0 and Multiplier 1 e Assure that the molbloc upstream or downstream pressure is properly set and held constant throughout the calibration e Tare the molbox at the beginning of the test and preferably just before taking data at each test point e sure to fully purge the complete test system of one gas when using a new gas so that the gas flow when making measurements is composed 100 of the expected gas e Assure that the molbloc and reference standard mass flow measurements are synchronized If the flow standard operates on a fixed measurement cycle as is the case with standards based on rate of volume or pressure change the averaging time of the standard and the molbloc must coincide precisely e Set the reference mass flow standard to measure the gas that is flowing Do not attempt to use gas conversion or K factors e Verify the repeatability of your measurement system Run an identical Verification Test three times under conditions that are as constant as possible Evaluate the evolution in the disagreements between the molbloc and the reference mass flow s
10. for changes in operating pressure Therefore adjustments made to a molbloc using CalTool for molbloc must be made using data collected at a single stable upstream or downstream molbloc pressure and following the calibration the molbloc must always be used at the upstream or downstream pressure at which it was calibrated This is the equivalent of a single P calibration see molbox Operation and Maintenance Manual CalTool for molbloc makes separate gas specific adjustments for each gas that is flowed Therefore individual calibrations and molbloc adjustments must be made for each desired gas CalTool for molbloc can be used to add gas calibrations for a molbloc Added gas calibrations like all molbloc calibrations using CalTool for molbloc are only valid at the upstream or downstream pressure at which the molbloc is calibrated This is the equivalent of a single P calibration see molbox Operation and Maintenance Manual CalTool for molbloc includes all the tools necessary to run comparisons between molblocs and a mass flow standard acquire data from the comparison calculate new calibration coefficients and write the coefficients to the molbloc It also includes tools to enter test data manually edit test data view calibration results change the molbloc calibration date and create and load molbloc restore files 4 As with any calibration the results of a molbloc calibration are only as good as the mass flow standard used as a ref
11. normally used in a molstic calibrate the molbloc mounted in the molstic with the molstic pressure regulator at its normal setting CalTool for molbloc adjustments are only valid for the operating pressure at which the calibration comparison is performed Install a means to set a stable flow rate over the range of the molbloc This could be a manual needle valve a mass flow controller or a component of the mass flow standard If the molbloc is normally used at an elevated static pressure with a constant upstream pressure the flow control element is usually placed downstream of the molbloc If the molbloc is used downstream with atmospheric or near atmospheric downstream pressure the flow control device is usually placed upstream of the molbloc Install a valve to shut off the flow upstream of the molbloc and the reference mass flow standard Connect a supply of the gas to be calibrated Generally gases with purity of 99 99 or better should be used to achieve normal molbloc specifications RUNNING A CALIBRATION Running the molbloc calibration consists of comparing the measurements of molbloc molbox and the mass flow standard used as a reference at various flows within the molbloc range and logging data at each flow point To run the molbloc calibration Purge the complete system to clear the old gas with the new gas The gas flowing through the molbloc and the mass flow reference must be pure when running the calibration To purge the mol
12. reference molbox readings are automatically synchronized To set up for automatic data acquisition from a molbox as the reference mass flow standard set up the reference molbox interface using Setup Interface If the reference interface is other than lt None gt CalTool will always try to communicate via the interface when a test isrun To return to manual entry of reference flow values set Setup Interface Reference to None see Section 4 2 1 3 14 PRECAUTIONS TO ASSURE GOOD MEASUREMENTS To help minimize additional uncertainties in the comparison between the test molbloc molbox and the mass flow standard used as a reference consider the following e Assure that there are NO leaks in the system Leaks cause the flow through the molbloc and the reference to be different making a valid comparison of the two impossible e Verify that the flow unit of measure for the molbloc and the mass flow standard are identical Consider the reference temperature on volumetrically based units of mass flow e Verify that the calibration gas setup CalTool the gas expected by the reference mass flow standard and the gas actually flowing are the same sure to calibrate the molbloc for the correct range for the gas and operating pressure Look the range up in the range charts in Section 6 e Set the test molbox stability criterion to an acceptable value for the pressure dependent flow range Typically 0 005 96 FS s is used
13. tests and calculate as left molbloc coefficients and data from a data file The Calibration menu includes the following selections Calibration Test Verification Test Calculation and Exit 4 1 1 CALIBRATION TEST Calibration Test is used to run a comparison of a molbloc and a mass flow standard The test ends in the calculation of new calibration coefficients and as left calibration data The Calibration Test automatically acquires data from the molbloc molbox at each flow point of the test and logs it to a data file dat For a Calibration Test to run CalTool must be able to establish remote communications with molbox to which a molbloc is connected Use Setup Interface Test molbox gt see Section 4 2 1 to set up communications with the test molbox In a Calibration Test the readings of the reference mass flow standard are entered manually or can acquired automatically if the reference mass flow standard is a molbox Use Setup Interface Reference see Section 4 2 1 to set up communications with the reference molbox For manual reference mass flow entries standard Setup Interface Reference must be set to None The test gas the gas for which the molbloc is being calibrated and that will be flowed when running the calibration test must be selected prior to running the Calibration Test Use Setup Test Gas to select the test gas see Section 4 2 2 A major benefit of using the
14. to identify operating and applications advice and additional explanations 1999 DH Instruments Inc Page iv CalTool for molbloc User s Manual 1 INTRODUCTION CalTool for molbloc is a PC based calibration utility intended to be used to adjust molbloc mass flow elements to agree with a mass flow reference at a particular operating pressure CalTool is run on a PC that is interfaced with a molbox1 or molbox RFM mass flow terminal CalTool runs mass flow intercomparisons collects intercomparison data calculates new molbloc calibration coefficients predicts and displays test data with the new coefficients and writes new calibration coefficients to the molbloc molblocs and molbox are normally calibrated as independent elements The molbox calibration consists of calibrating the molbox pressure transducers See the molbox Operation and Maintenance Manual for molbox calibration information 1 1 PRINCIPLES 1 1 1 HOW molbloc molbox DETERMINES MASS FLOW molbloc mass flow elements are laminar flow elements intended to be used with a molbox molbox1 or molbox RFM mass flow terminal The molbox measures the temperature of the molbloc and the molbloc upstream and downstream pressures Using the pressure and temperature information and gas characteristics stored in molbox memory molbox calculates the density and viscosity of the flowing gas From the density and viscosity of the flowing gas the differential pressure across the mo
15. written to the molbloc EEPROM If you do not want to activate the new calibration coefficients click the lt Calculation Activation gt window s close control box or go directly to any other CalTool menu option 1999 DH Instruments Inc Page 10 CalTool for molbloc User s Manual H If desired verify the calibration as left data by rerunning the test To verify rerun the test following Steps 6 through 9 but in Step 6 use Calibration Verification Test see Section 4 1 2 A verification test ends without going to the calculate and activate calibration options If desired Verification Test data files can still be used to generate new calibration coefficients by using the Calibration Calculate option see Section 4 1 3 Repeat Steps 1 through 13 for each calibration gas that is to be included on the molbloc Consider changing the molbloc calibration date see Section 4 4 5 Create a molbloc restore file using Tools Create Restore File The molbloc restore file provides a backup record of all the information on the molbloc s EEPROM so that should the EEPROM become corrupted or damaged its content can be restored see Section 3 3 3 1 3 USING A molbloc molbox AS THE REFERENCE MASS FLOW STANDARD In some cases the reference mass flow standard used in a molbloc calibration may be another molbloc molbox system In this case readings from the reference can be taken automatically and the test and
16. 1999 DH Instruments Inc Page 12 CalTool for molbloc User s Manual 3 3 CREATING AND USING molbloc RESTORE FILES Every molbloc is equipped with an EEPROM in which its specific identification and calibration information is stored The complete molbloc EEPROM contents can be saved in restore files brs The restore files can be used to reload the molbloc information if the molbloc EEPROM is accidentally altered or corrupted DHI maintains restore files on every molbloc it delivers new or on which it performs a recalibration These restore files and a file loading utility can be provided to molbloc users to recover their molbloc data However if molbloc calibration coefficients have been altered using CalTool the restore files maintained by DHI are no longer current CalTool includes a tool to create restore files and load them onto molblocs so that CalTool users can maintain their own restore files It is recommended that a molbloc restore file brs be created and archived every time a molbloc is calibrated and verified using CalTool To create and or load molbloc restore files use Tools Create Restore File and Restore molbloc see Sections 4 4 3 4 4 2 Page 13 1999 DH Instruments Inc for molbloc User s Manual 1999 DH Instruments Inc Page 14 CalTool for molbloc User s Manual 4 MAIN MENU OPTIONS 4 1 CALIBRATION MENU The Calibration menu offers selections to run
17. 2E2 SIZE 5E2 SIZE 1E3 SIZE 5E3 SIZE 1E4 Argon Helium Sulfur Hexafluoride Xenon Butane Ethane Ethylene Hydrogen Methane Propane Carbon Tetrafluoride Hexafluoroethene Trifluoromethane Air Carbon Dioxide Carbon Monoxide Nitrous Oxide Oxygen A bold value indicates that the maximum flow is limited by the maximum Reynolds number value of 1 200 which is reached before the normal differential pressure range is reached In that case the second value gives the minimum flow for which measurement uncertainty accuracy is a of the measured value Measurement Specifications in the molbox Operation and Maintenance Manual Page 35 With the microrange option this value is divided by 10 see molbloc Flow 1999 DH Instruments Inc for molbloc User s Manual Table 4 molbloc Ranges with High Pressure Calibrations molbloc SIZE AND FULL SCALE FLOW sccm SIZE SIZE SIZE SIZE SIZE SIZE SIZE 5E1 1E2 2E2 5E2 1E3 5E3 1E4 Nitrogen Argon Helium Sulfur Hexafluoride Xenon Butane N A Ethane 20 000 13 800 Ethylene 22 000 12 700 Hydrogen 130 000 ul m lt lt EH Methane 42 000 12 000 Propane Carbon Tetrafluoride Hexafluoroethene Trifluoromethane FLUORO CARBONS Air
18. 63E 05 As Left Calibration Activation Date Cg Beta 1991116 3 101733E 16 4 422007E 05 Test Data Ref Flow molbloc Flow diff Rdg Err As Left flow As Left Diff As Left Rdg Err 108 131 107 963 0 168 0 155 108 1305 0 0005 0 000 78 7568 78 6797 0 0771 0 098 78 7478 0 009 0 011 61 9754 61 9475 0 0279 0 045 61 9771 0 0017 0 003 43 1317 43 141 0 0093 0 022 43 1428 0 0111 0 026 20 9995 21 0057 0 0062 0 030 20 996 0 0035 04017 molbloc RESTORE FILE Restore files are created by CalTool using Tools Create Restore File see Section 3 3 Restore files contain all the information from a molbloc EEPROM They are intended to restore the complete molbloc EEPROM information should the EEPROM become corrupted or to return the molbloc to a known previous state Restore files contain molbloc header information and the molbloc calibration coefficients manipulated by CalTool for each gas for which the molbloc is calibrated Restore files also contain confidential molbloc characterization information that cannot be viewed by the user Any modifications to the restore file will make it unusable to CalTool Tools View molbloc Calibration see Section 4 4 4 allows the public information contained in a molbloc EEPROM to be viewed Page 31 1999 DH Instruments Inc for molbloc User s Manual The default restore file name is molbloc sn NNNN Restore brs where e molbloc sn file label
19. CalTool for molbloc A PC Based Calibration Utility For molbloc Flow Elements User s Manual 1999 DH Instruments Inc CalTool for molbloc User s Manual High pressure liquids and gases are potentially hazardous Energy stored in these liquids and gases can be released unexpectedly and with extreme force High pressure systems should be assembled and operated only by personnel who have been instructed in proper safety practices 1999 DH Instruments Inc All rights reserved Information in this document is subject to change without notice No part of this document may be reproduced or transmitted in any form or by any means electronic or mechanical for any purpose without the express written permission of DH Instruments Inc 4765 East Beautiful Lane Phoenix AZ 85044 5318 USA DH Instruments makes sincere efforts to ensure 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 does not constitute an endorsement by DH Instruments of that product 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 versio
20. Calibration Test option is that CalTool writes the molbloc as received calibration coefficients in the data file This information is verified prior to activating new coefficients to help ensure the validity of the calibration Page 15 1999 DH Instruments Inc CalTool for molbloc User s Manual Running a Calibration Test When Calibration Test is selected CalTool attempts to establish communications with the test molbox read the coefficients of the molbloc attached to the molbox and set the molbox for the test gas If communications with a test molbox cannot be established a Calibration Test cannot be run and an error message is displayed If communication with a test molbox is not possible consider creating a test file manually using Data Create see Section 4 3 1 Once communication with a test molbox and a reference molbox if present has been established CalTool prompts the operator to identify the reference mass flow standard The labels entered here will be stored in the Calibration Test data file dat for future reference identification Following entry of the reference identification CalTool prompts the operator for entry of the fixed upstream or downstream test pressure at which the molbloc is being calibrated The pressure value and pressure unit should be entered These will be stored in the Calibration Test data file dat This information is important since the calibration performed by CalToo
21. RANGE DESIGNATION DESIGNATION 10 sccm 1E1 50 sccm 5E1 100 sccm 1E2 200 sccm 2E2 500 sccm 5E2 1 sim 1E3 5 sim 5E3 10 sim 1 4 30 slm 3E4 6 2 molbloc PRESSURE DEPENDENT CALIBRATION TYPES All CalTool for molbloc calibrations are of the Single P type meaning that they are performed at a specific upstream or downstream operating pressure The valid molbloc range for a given gas depends on the calibration pressure If the calibration pressure is a molbloc downstream pressure of atmospheric pressure or a molbloc upstream pressure between 250 and 325 kPa absolute 36 and 48 psia the molbloc is considered to have a LOW pressure calibration molbloc ranges for various gases with low pressure calibrations are given in Table 3 If the calibration pressure is a molbloc upstream pressure between 325 and 525 kPa absolute 47 and 76 psia the molbloc is considered to have a HIGH pressure calibration molbloc ranges for various gases with HIGH pressure calibrations are given in Table 4 Extending the molbloc range beyond the ranges specified in Table 3 or Table 4 depending on their operating pressure may result in out of tolerance measurements 1999 DH Instruments Inc Page 34 CalTool for molbloc User s Manual 23 a lt lt 2 FLUORO CARBONS Nitrogen Table 3 molbloc Ranges with Low Pressure Calibrations molbloc SIZE AND FULL SCALE FLOW sccm SIZE 5E1 SIZE 1E2 SIZE
22. a file CalTool checks for invalid or missing data Once valid data has been entered into all required fields the Save Data File As window is presented Accept the default file name and path or edit as desired Use Clear to erase all data from the entry form This is useful when creating multiple data files to get a clean form after each save without re selecting the Data Create option Page 23 1999 DH Instruments Inc H CalTool for molbloc User s Manual A Manual data files do not contain the as received molbloc calibration coefficients so CalTool cannot verify them prior to activating a calibration For this reason when using manually created data files to activate a calibration it is critical to assure that the molbloc has the same calibration coefficients during calibration calculation and activation as it did during the actual data gathering process Failure to assure consistency is likely to result in invalid calibrations since CalTool will be using incorrect data in its calculations 4 3 2 gt E SOFTWARESNCTMLBLOC DATA molbloc 217 N2 dat x Parameters Gas 2 Nitrogen z Test Pressure 274 kPa Flow Unit sccm Header Serial Number 21 Nominal Range 00 scem Clear molbox Model molbox Ver 4 02c Serial Number 407 Reference Model molboxi Ver 4 02 Identification Station 6 Serial Number molbox 430 molbloc 723 Reference
23. ange The recommended distribution is 10 25 50 75 100 FS The molbloc range depends on the molbloc size the test pressure and the calibration gas See Section 6 for molbloc gas and pressure dependent range tables The test may be aborted at any time without creating a data file by clicking the Abort Test icon 1999 DH Instruments Inc Page 16 CalTool for molbloc User s Manual For a normal test ending which creates a data file click the Test gt icon After confirming that the test should be ended the lt Save Data File As gt window is presented Edit the name and or path of the data file as desired and click lt Save gt When running a Calibration Test after the data file has been saved CalTool goes directly to the lt Calculation Activation gt window see Section 4 1 3 4 1 1 1 CALIBRATION TEST VERIFICATION TEST RUN SCREEN The run screen is active when a Calibration Test or Verification Test is running The screen can be scaled by dragging its corners or positioned by dragging its title bar at any time while a test is running The run screen provides a convenient display of the test molbloc flow conditions Reynolds number upstream pressure downstream pressure average temperature as well as the current program status The round red green indicator in the upper left hand corner is the ready not ready indicator The indicator is green when the test molbloc molbox flow becomes ready by me
24. box If remote communication with a test molbox cannot be established an error message displays The lt Remove Gas gt window is displayed including a listing of all the gases except N2 for which there are calibration coefficients on the connected molbloc Click the checkbox next to the gas or gases to be removed Thenclick lt Remove Gas gt After confirmation the calibration for the selected gas is removed from the molbloc The nitrogen N2 gas calibration cannot be removed from a molbloc Select Exit to close the lt Remove Gas gt window PAN Kemoving a gae from a molbloc ie not a revereible process To restore the gae a new calibration will have to be run a restore file will have to be loaded for the molbloc Remove gas x Remove Gas Exit Figure 7 Remove Gas Window 1999 DH Instruments Inc Page 26 CalTool for molbloc User s Manual H 4 4 2 RESTORE molbloc restore changes the complete molbloc EEPROM file including header information and all gas calibrations Restore molbloc does not work on gases individually it works with the complete restore file which contains ALL molbloc data Restore molbloc is used to restore a molbloc whose EEPROM has been corrupted or to return a molbloc to a previous state Using restore molbloc requires a valid restore file brs Restore files are created using Create restore file see Section 4 4 3 DHI technical service maintains re
25. box use the molbox purge function if the molbox does not have the purge function cycle the molbox pressure with the new gas repeatedly consider downloading new molbox software from www dhinstruments com software Verify that the molbloc upstream or downstream pressure when flowing is the molbloc s normal operating pressure This pressure must remain stable and constant throughout the calibration process Press P amp T on the molbox keypad to view the molbloc upstream and downstream pressures If the molbox is in remote mode remote LED lit press ESCAPE on the molbox keypad to return to local mode so front panel is active 1999 DH Instruments Inc Page 8 CalTool for molbloc User s Manual H Connect the calibration gas supply Generally gases with purity of 99 99 or better should be used to achieve normal molbloc specifications The calibration gas must be the gas for which the molbloc is to be calibrated no surrogates or k factors are possible Set the molbox measurement parameters Press UNIT on the molbox keypad to set the desired mass flow unit of measure Assure that the molbox mass flow unit and the mass flow reference standard mass flow unit are identical including the reference conditions in the case of volumetrically based mass flow units Press SETUP lt 5stab gt on the molbox keypad to set the molbox stability criterion ready not ready indication CalTool for molbloc uses the molbo
26. box consists of calibrating the molbox pressure transducers and possibly verifying its ohmic measurement system which reads the molbloc platinum resistance thermometers molbox calibration procedures are described in the molbox Operation and Maintenance Manual Calibration of a molbloc consists of comparing the mass flow measured by the combination of the molbloc and a calibrated molbox to a suitable mass flow standard flowing the gas for which the calibration is being performed Since the molbloc is a static stainless steel element characterized by proprietary calibration coefficients determined in the original factory calibration an out of tolerance molbloc is usually considered to require repair CalTool for molbloc software is available for facilities requiring the capability to adjust molblocs to agree with their mass flow standard 1 1 3 HOW CALTOOL FOR molbloc WORKS CalTool for molbloc supports the adjustment of certain proprietary molbloc coefficients to fit the molbloc mass flow measurements to a mass flow standard for a specific gas at a specific molbloc operating pressure The proprietary molbloc calibration coefficients manipulated by CalTool for molbloc are designated and beta is the value of C extrapolated to a Reynolds number of zero i e null flow and is the slope of the variation of C with Reynolds number CalTool for molbloc does not adjust molbloc calibration coefficients relating to compensation
27. different file extension res The default result file name is molbloc sn GGGG res where e molbloc sn file label e the molbloc serial number e GGGG the calibration gas used in the Calibration or Verification Test from which the result file was created e res automatic file extension of a result file 1999 DH Instruments Inc Page 30 CalTool for molbloc User s Manual BHI 9 If the result file is created from dat file resulting from a Verification Test Verify is NOT included in the res file name The default path for a result file is CalTool for molbloc Data res If a new file location is selected while saving all result res files will be saved to the selected path by default until another path selection is made The result file is a comma delimited file for easy use in other applications In the sample result file all fields that appear in italics are fixed fields created by CalTool The calibration instruments and process determine the remaining information Sample Result File 5 4 Wed November 24 1999 09 58 AM Test Gas Test Pressure Flow Unit N2 274 kPaa sccm Reference Model Reference ID Reference SN 1 1 Ver4 02c Station 6 molbox 430 molbloc 723 molbox Model molbox SN molboxl Ver4 02c 407 molbloc SN Nominal Range Cal Mode 1281 100 0 scom Recalibration As Received Calibration Cal Date Cg Beta 19991116 3 104707E 16 5 8489
28. erence and the integrity of the calibration comparison process Page 3 1999 DH Instruments Inc H CalTool for molbloc User s Manual 1999 DH Instruments Inc Page 4 CalTool for molbloc User s Manual 2 GETTING STARTED This section explains how to install CalTool for molbloc on your computer and provides an overview of the startup procedures 2 1 SYSTEM REQUIREMENTS CalTool for molbloc requires a minimum PC configuration and a molbox1 or molbox RFM for data collection and communication with the molbloc If your PC does not meet these minimum requirements the software will not run as designed 2 2 Windows 95 98 or NT 75 MHz Pentium 8 Mbytes of Ram 7 Mbytes of free hard disk space At least one available RS232 port and or National Instruments Corporation IEEE 488 interface card INSTALLING CALTOOL FOR molbloc 2 2 1 e WINDOWS 95 98 NT Start Windows operating system Insert the CalTool for molbloc CD into your CD drive The CalTool setup program will automatically run If it does not press the Start button then select Run In the Run dialog box type D disk1 setup exe depending on label of the CD drive you placed the installation disk The setup program will step through the installation process prompting you for entry of the necessary information To run CalTool for molbloc press the Start Button select Programs then select CalTool for molbloc and click on the CalTool
29. eting the molbox stability criterion see the molbox Operation and Maintenance Manual ready not ready section The blue status panel tracks the current test point and averaging information The lt Current gt display indicates the point number within the overall test of the point that is being taken or that will be taken when the Take Point icon is clicked The Avg Time display indicates the molbox averaging time for a point The time counts down to zero when CalTool is taking a point The bottom line of the panel indicates the current program status IDLE when a test is NOT running RUNNING when a test is running but a point is NOT being taken lt AVERAGING gt while counting down the averaging period when taking a point DATA ENTRY when the user must make an entry lt TARE gt when the CalTool tare screen is active and the user has the ability to tare the test or reference molbox Calibration Test Hun Screen x fl mi Reading Error Current Point 1 LIT Avg Time 10s RUNNING Avg Temperature C Figure 2 Calibration Test Verification Test Run Screen Page 17 1999 DH Instruments Inc H 4 1 1 2 The Run Test Toolbar is used to control a test Calibration or Verification Test is running executes various test functions CalTool for molbloc User s Manual RUN TEST TOOLBAR The Toolbar is active when a Clicking the Run Test Toolbar icons The Run Test Toolbar ic
30. icon Page 5 1999 DH Instruments Inc CalTool for molbloc User s Manual 2 2 2 RUNNING THE PROGRAM Before running CalTool establish a remote connection between a molbox1 or molbox RFM and the host PC Do this by connecting your PC to the molbox using a standard RS232 cable and connecting one of the PC s communications ports to the molbox s Com1 port National Instruments Corporation IEEE 488 cards are also supported by CalTool for remote communication using the molbox s IEEE 488 interface IEEE 488 users should connect a IEEE 488 cable to the IEEE 488 port on the molbox and to the desired IEEE 488 card in the host PC See the molbox Operation and Maintenance Manual Remote Section for additional information on molbox communication interfaces and settings Once you have set up the interface between the molbox and the PC you are ready to run CalTool Click the CalTool Icon in the CalTool program group in the Start menu When CalTool for molbloc loads it assumes the communication settings that were in use when the program was last run All program options that require a remote interface with a molbox use these settings See Section 4 2 1 to change CalTool interface setups 1999 DH Instruments Inc Page 6 CalTool for molbloc User s Manual 3 NORMAL OPERATING PROCEDURES 3 1 TYPICAL START TO FINISH CALIBRATION PROCEDURE The typical start to finish calibration procedure includes Setting up to run the ca
31. ing the actual data gathering process Failure to follow this step may result in large discrepancies between the predicted as left molbloc error and the actual as left error If the manually created data file is used to activate a calibration the current molbloc coefficients are automatically written to the data file In the sample data file all fields that appear in italics are fixed fields created by CalTool The calibration instruments and process determine the remaining information Sample data file molbloc SN 1281 molbloc Range 100 0 sccm Cal Date Cg Beta 19991116 2 8248E 16 3 918E 05 molbox Model molboxl Ver4 02c molbox SN 407 Test Gas N2 Test Pressure 274 kPaa sccm Reference SN molbox 430 molbloc 723 Reference ID Station 6 Reference Model molboxl Ver4 02c Test Data Ref Flow molbloc Flow molbloc Re Diff Rdg Err 14 3762 13 0663 21 24 1 3099 9 112 23 8636 21 7522 35 36 2 1114 8 848 42 0102 38 2995 62 26 3 7107 8 833 69 9469 63 788 103 7 6 1589 8 805 108 249 98 7883 160 59 9 4607 8 740 5 3 RESULT FILE A result file is created by CalTool from a data file see Section 5 2 and the results of the calculation function when a calibration is activated see Section 4 1 3 The result file is identical to the data file but it contains additional information including the calculated as left molbloc calibration coefficients and as left test data for the test gas The result file also has a
32. l Range Designations sse 34 Table 3 molbloc Ranges with Low Pressure Calibrations 2 35 Table 4 molbloc Ranges with High Pressure 36 Page iii 1999 DH Instruments Inc CalTool for molbloc User s Manual ABOUT THIS MANUAL Manual Conventions This manual is intended to provide the user with the information necessary to use CalTool for molbloc software to adjust molbloc mass flow elements Before using the manual take a moment to familiarize yourself with the table of contents structure Do not attempt to use CalTool for molbloc for molbloc without using this manual to understand its principles and operation Invalid molbloc calibrations can result from incorrect use of CalTool Certain words and expressions have specific meaning as they pertain to CalTool molbloc and molbox The Glossary Section Section 7 is useful as a quick reference for definitions of specific words and expressions as they are used in the manual indicates CalTool menu tab selections or icons for example Data Menu or tab selection paths are always described hierarchically from highest to lowest level For example Tools Options indicates COMPASS text displays such as screen names field names prompts warnings and instructions For example Enter user ID gt CAUTION is used in the manual to identify user warnings and cautions NOTE is used in the manual
33. l is valid only at the test pressure Following entry of the test pressure the Run Screens is presented see Section 4 1 1 1 current status is RUNNING and it actively reads and displays a variety of molbloc measurements The Run Test Tool Bar see Section 4 1 1 2 is used to interact with the CalTool Run Screen Once a flow point has been set and stabilized ready not ready indicator green click the Take Point icon or press ENTER on the PC to log the point This causes CalTool to read the molbox for the averaging time The reading can be interrupted by clicking the Abort Point icon or by pressing ESC on the PC The can be tared prior to taking the point by clicking the lt Tare molbox gt icon see Section 4 1 1 2 After CalTool has logged the averaged molbox reading the user is prompted to enter the reference mass flow standard reading Do not include the unit of measure when entering the reference mass flow reading Following entry of the reference mass flow reading CalTool fills in the Test Data Entry window s data grid with the information for the point just taken and returns to the RUNNING status Test points can be repeated by clicking the Repeat Test Point icon Each click moves back one point and all points forward must then be retaken A maximum of 22 and a minimum of 3 data points may be included in a Calibration Test For best results the points should be distributed across the flow r
34. lbloc and molbloc specific calibration coefficients stored on the molbloc EEPROM molbox calculates the mass flow through the molbloc see Figure 1 The model used by molbox to calculate molbloc flow is proprietary molbloc specific calibration coefficients are determined in the original factory calibration Since the molbloc is a static stainless steel element the molbloc calibration coefficients are stable over time Page 1 1999 DH Instruments Inc CalTool for molbloc User s Manual 8 IPT Where _ _ qm id Z pr R T T Determined by Known from Determined from Measurement Gas Properties Gravimetric Calibration P M P Zi T Nen And qm mass flow kg s upstream absolute pressure Pa 5 downstream absolute pressure Pa 65 2 T absolute temperature of gas Tos dynamic gas viscosity under P T conditions Paes C geometry of molbloc flow path and m Reynolds number dependence Re Reynolds number molecular weight of the gas g mol Zen compressibility factor of the gas under P T conditions R universal gas constant 7 kg k r radius of the piston m 1999 DH Instruments Inc Page 2 Figure 1 molbloc molbox Mass Flow qm Determination CalTool for molbloc User s Manual H 1 1 2 RECALIBRATION OF molbloc molbox The molbox mass flow terminal and molbloc mass flow elements are calibrated separately Calibration of a mol
35. libration see Section 3 1 1 Running the calibration see Section 3 1 2 Calculating and evaluating calibration results see Section 3 1 2 Writing new calibration coefficients to the molbloc see Section 3 1 2 Verifying calibration results if desired see Section 4 1 2 9 O Creating the molbloc restore file see Section 3 3 separate calibration is required for each gas with which the molbloc is to be used Page 7 1999 DH Instruments Inc H 3 1 1 CalTool for molbloc User s Manual SETTING UP TO RUN A CALIBRATION Prior to calibrating a molbloc for the first time a restore file of the existing molbloc should be created if one is not available The restore file will allow the molbloc to be restored to its as received state should you wish to reverse the calibration process To set up and prepare the molbloc for calibration 3 1 2 Connect the molbloc to a calibrated molbox following the instructions in the molbox Operation and Maintenance Manual The molbox must be properly calibrated for the molbloc calibration to be valid Connect the molbloc to be calibrated in series with the mass flow standard that is serving as the reference The molbloc must be installed so that the upstream or downstream pressure will be stable throughout the calibration The fixed upstream or downstream pressure must be the same pressure at which the molbloc will be used in normal operation If the molbloc is
36. low regimes RPT Reference Pressure Transducer The pressure transducers used in molbox1 and molbox RFM are referred to as RPTs Single P Calibration A molbloc calibration option which is valid at a single specified operating pressure Stability Limit A limit expressed in units of flow per second e g sccm second The stability limit is used as the Ready Not Ready criterion Ready lt gt if rate is less than stability limit Not Ready lt T gt gt lt if rate is greater than stability limit See also Rate 1999 DH Instruments Inc Page 38 CalTool for molbloc User s Manual Surrogate Gas Test Pressure Upstream A gas whose behavior from the standpoint of a device under test is similar to the process gas for which the device is to be characterized and used A surrogate gas is often used in calibration and testing when the process gas cannot be used for safety or cost reasons The pressure at which the molbloc is being calibrated and will be used To use CalTool properly the test pressure must be a constant upstream or downstream value within the limits of the molbloc pressure dependent calibration options See the molbloc pressure dependent calibration types and ranges in Section 6 Location of point A relative to point B in a flow system in which point A is at a different location in the opposite direction of the flow For example the upstream molbloc pressure po
37. molbox when a gas not calibrated on a molbloc is used Regardless of the method selected consistency is most important Select Tools Change molbloc Calibration Date to read the molbloc and display the current calibration date Edit the date as desired When entering and viewing the date the format must be YYYYMMDD where e YYYY 4 digit year e MM 2 digit month e DD 2 digit day January 23 1999 must be entered and displays as 19990123 It is necessary to include a leading zero for month and day values that are less than 10 to insure the field always contains 8 characters When the molbloc has an invalid date stored in the EEPROM CalTool displays the default calibration date 19800101 F the molbloc calibration date displayed and changed by Change molbloc Calibration Date is included in the View molbloc Calibration feature data files dat and result files res 4 5 WINDOW MENU The Window menu allows selection of which window to place on top among all the windows currently open in CalTool Each new window opened in CalTool automatically adds to the list of available selections 1999 DH Instruments Inc Page 28 5 1 CalTool for molbloc User s Manual 5 CALTOOL FILE TYPES AND CHARACTERISTICS INTRODUCTION CalTool for molbox creates and manipulates three different types of files which are detailed in Sections 5 2 through 5 4 These include 5 2 Data Files dat Files into which CalTool log
38. n taring is complete use the close control box in the top right hand corner to close the tare display and return to the Run Screen See the molbox Operation and Maintenance Manual for complete information on taring and its importance to good measurements The lt Tare icon is not active while taking a point Display Graph Cause the lt Plots gt window to be displayed with a real time of reading error plot of the test that is running End Test Used for a normal test ending after execution of the last data point After confirmation causes the lt Save Data File As gt window to be presented Accept the default data file name and path or edit and select lt Save gt to save the data file If the test was a Calibration Test operation proceeds to the lt Calculation Activation gt screen 1999 DH Instruments Inc Page 18 CalTool for molbloc User s Manual H Table 1 Tools Available on the Run Test Toolbar Continued ICON DESCRIPTION Used to completely abort a Calibration or Verification Test without saving data After x confirmation causes test execution to stop and status to go to lt IDLE gt Abort Test Avg Time Enter the time in seconds over which molbox readings are to be averaged The minimum averaging time is 5 seconds and the maximum is 9999 seconds The Text Entry averaging time setting affects both the test and reference molbox if the reference mas
39. ns the English version predominates DH Instruments DH DHI molbloc molbox molbox1 and CalTool are trademarks registered and otherwise of DH Instruments Inc Document No 550117 991210 Printed in the USA 1999 DH Instruments Inc CalTool for molbloc User s Manual TABLE Or CONTENTS TABLE OF CONTENTS cua Fu ks accusa nas sa veu i FIGURES iii TABLES ihi da et d ost HE M OIN MM MEM UN C qd iii ABOUT THIS iv 1 INTRODUCTION 2 1 1 1 PRINGIPLES 1 1 1 HOW molbloc molbox DETERMINES MASS FLOW 1 1 2 RECALIBRATION 1 1 3 HOW CALTOOL FOR molbloc 8 40 001 2 GEFTNG EA REX SPESE VN MUS 5 2 1 SYSTEM REQUIREMENT S 5 2 2 INSTALLING CALTOOL FOR molbloc 2 2 1 WINDOWS 95 98 222 RUNNING THE PROGRAM 3 NORMAL OPERATING PROCEDURES 31 TYPICAL START TO FINISH CALIBRATION 3 1 1 SETTING UP TO RUN A CALIBRATION 3 1 2 RUNNING A CALIBRATION cccssssssssssssssssssssssssssssssssssessssesssssssssssseesssstessssueesseseesses 3 1 3 USING A molbloc molbox AS THE REFERENCE MASS FLOW STANDARD 3 1 4 PRECAUTIONS
40. on 4 1 1 1 Page 9 1999 DH Instruments Inc CalTool for molbloc User s Manual Run the test flow points and log the data at each point The recommended test points are 10 25 50 75 100 FS of the molbloc range for the calibration pressure and gas The minimum number of points for CalTool to calculate calibration coefficients is three The procedure for each test point is Use the flow setting device to set the flow to the desired flow increment and allow the flow to stabilize until the ready not ready indicator on the CalTool run test screen indicates green For certain reference flow standards particularly those that are based on a fixed measurement cycle this may require a bypass valve to flow by the standard Tare the molbox by clicking on the Tare icon on the Run Test Toolbar see Section 4 1 1 2 Adjust the Avg Time on the Run Test Toolbar if desired This setting determines the amount of time over which molbox readings will be averaged when the data point is recorded When the reference mass flow standard is based on a fixed measurement cycle it is important that the CalTool averaging time and the standard s measurement cycle be synchronized When ready to take the flow data point click the Take Point icon on the Run Test Toolbar or press ENTER on the PC The lt Run Screen gt displays lt AVERAGING gt while the averaging time counts down and the molbox average flow reading is logged P
41. ons include Take Point Abort Current Point Repeat Test Point Display Graph End Test Abort Test Average Time Tare Table 1 Tools Available on the Run Test Toolbar ICON DESCRIPTION Starts the Take Point sequence to take a test point in a Calibration or Verification Test The Take Point sequence includes start molbox reading averaging cycle and Take Point average over time period log average molbox reading to data file acquire reference mass flow standard reading by manual entry or automatically Pressing the ENTER on the PC key as a shortcut to this function The averaging time is determined by the Avg Times field on the toolbar Abort Point Interrupts the Take Point process and aborts the current point Press ESC on the PC as a shortcut to this feature Repeat Point Used to retake a test point Decrements the current point back once each time it is clicked If clicked several times to go back more than one point all the points must be retaken The lt Repeat Point gt icon is not active while taking a point sr Tare molbox Starts the Tare molbox sequence to tare the test or reference molbox After selecting which molbox to tare and whether to tare on the upstream or downstream molbloc port the lt Tare molbox gt window displays Pressing the lt Tare gt button causes the molbox to execute the tare function and activate the new tare s If an invalid tare occurs repeat the process Whe
42. ool program 1999 DH Instruments Inc Page 20 CalTool for molbloc User s Manual 4 2 SETUP MENU The Setup menu offers selections to set up communications interfaces with the test and the reference and to select the test gas with which tests are run The Setup menu includes the following selections Interface and Test Gas 4 2 1 INTERFACE Interface is used to set up the interface with the test molbox and the reference mass flow standard Many CalTool functions require a valid interface with a test molbox To set up CalTool communication interfaces select Setup Interface The lt Interface Setup window is presented In the Device selection box select Test molbox gt to set the interface to the test molbox or References to set up the interface to the reference The current interface for the selected device is displayed in the Remote Interface box The drop down list includes the three interface choices that CalTool supports lt RS232 gt lt 488 gt and None lt gt is only available for reference since a remote interface with a test molbox is required lt RS232 gt lt IEEE 488 gt are apply for the reference only if the reference is a molbox CalTool does not support remote communications with references other than a molbox If lt RS232 gt is selected the com port and port settings can be changed by clicking any of the RS232 settings fields and making the
43. r while a restore file is being created make sure the file is deleted and retry Creating a restore file does not modify any of the molbloc EEPROM contents it only saves them Page 27 1999 DH Instruments Inc CalTool for molbloc User s Manual 4 44 VIEW molbloc CALIBRATION View molbloc Calibration is used to view the current molbloc header information and gas CalTool accessible calibration coefficients for all the gases for which the molbloc has calibrations To view the calibration information of the molbloc that is connected to the test molbox select Tools View molbloc Calibration After CalTool reads the molbloc EEPROM the EEPROM information is displayed on the text display The view option is a good check point for molblocs that have recently been restored see Section 3 3 or to determine the gases for which a molbloc has calibrations 4 4 5 CHANGE molbloc CALIBRATION DATE Change molbloc Calibration Date is used to change the calibration date stored in the molbloc EEPROM Since each molbloc has only one calibration date CalTool does not automatically change the calibration date each time a new gas is added It is up to the user to define the purpose and use of the molbloc calibration date It is common practice to allow this date to always represent the last factory re calibration or the last Nitrogen calibration Nitrogen calibrations are significant because this calibration is used internally by the
44. relative to atmospheric pressure A factor representing the relationship between the process gas and a surrogate gas for a DUT The average pressure at which the molbloc is operated average of upstream and downstream pressure or if the molbloc pressure is held constant by an upstream or downstream regulator the value of the constant pressure Process Gas The gas for which a device under test is to be characterized or calibrated The gas that will actually flow in the device under test when it is used in a process Ready Not Ready PRT Platinum Resistance Thermometer The element used in molblocs to measure temperature Psia Pressure unit pounds per square inch absolute Pressure expressed relative to vacuum Psig Pressure unit pounds per square inch gauge Pressure expressed relative to atmospheric pressure Rate A molbox DISPLAY function in which the current rate of change of the flow in flow units second is displayed A measure of stability of the flow used by the molbox to make the ready not ready determination See also Stability Limit Indication of when flow is stable within the stability limit See also Stability Limit Reynolds Number A ratio of the inertia forces to the viscous forces in a flowing fluid This dimensionless number which is dependent on fluid viscosity density velocity and length of the flow field is often used to predict a boundary point between laminar and turbulent f
45. ress ESC on the PC or click the Abort Point icon to abort a point while averaging The lt Reference Flow gt window is displayed Enter the average reference flow observed over the same period as that over which the molbox flow was averaged When a second molbloc molbox is used as the reference CalTool automatically averages and logs the reference flow 9 Observe the results of the point in the Test Data Entry grid If you would like to repeat the point click once on the Repeat Test Point icon on the Run Test Toolbar Each click moves back one point Repeat Step 8 for each of the test points of the test End the test run by clicking the End Test icon on the Run Test Toolbar The Save Data File As window is displayed Q Save the test data file as is or modify the name and or path The lt Calculation Activation gt window is displayed Observe and evaluate the calibration results in the lt Calculation Activation gt window These include the new molbloc calibration coefficients for the calibration gas and the predicted as left data CalTool determines the as left values by recalculating the molbloc measured flow using the new molbloc calibration coefficients f the calibration results are acceptable activate the new calibration coefficients To activate the new calibration coefficients click Activate Calibration This causes the new calibration coefficients for the calibration gas used in the test to be
46. rt is upstream relative to the downstream pressure port because it is at a different location from the downstream port in the opposite direction of the flow Verification Test A test run by CalTool for molbloc that compares readings from a molbloc and a mass flow standard and creates a data file dat but does not go directly to the calculate and active calibration functions at the end of the test Verification tests are run with the intention of verifying a molbloc calibration Volumetrically Based Mass Flow Units Mass flow units of measure that are based on the quantity of gas that occupies a fixed volume under reference pressure and temperature conditions Page 39 1999 DH Instruments Inc for molbloc User s Manual 1999 DH Instruments Inc Page 40
47. s flow standard is a molbox The averaging time can be edited between points while a test is running 4 1 2 VERIFICATION TEST Verification Test is used to run a simple comparison of a test molbloc and a reference standard that does not end in calculation and activation of new molbloc calibration coefficients A Verification Test is identical to a Calibration Test in both setup and operation see Section 4 1 1 but the Verification Test does not go directly to Calculation Activation the test ends with a display message of the maximum Reading error and the default name of the resulting data file is Verify dat Calibration Test and Verification Test data files are identical in structure A Verification Test data file can be used with the Calculation function to determine new molbloc calibration coefficients and predict as left data if desired see Section 4 1 3 The Verification Test is normally used after a calibration to verify the predicted as left data It is also used for routine comparisons of molblocs and a reference standard 4 1 3 CALCULATION Calculation is used to calculate new molbloc coefficients and predicted as left data from a data file dat for example a data file that has been created or edited manually or a Verification Test data file This function also allows the results of the calculation to be activated by writing to the molbloc and creating a result file res When Calculation is selected
48. s information from Calibration and Verification Tests see Section 4 1 1 Result Files res File created from a data file after a calibration has been activated see Section 4 1 3 Includes the as left data calculated from the as received data results Restore Files brs Copies of the complete information contained in a molbloc EEPROM see Section 3 3 DATA FILE Data files are the files created by CalTool to store the information from a Calibration or Verification Test The default data file name is molbloc sn NNNN Verify GGGG dat where molbloc sn file label NNNN the molbloc serial number Verify label present only on files created by a Verification Test to distinguish them from a Calibration Test GGGG the calibration gas used in the Calibration or Verification Test dat automatic file extension of a data file Page 29 1999 DH Instruments Inc for molbloc User s Manual The default path for a data file is CalTool for molbloc Data dat If a new file location is selected while saving all data dat files will be saved to the selected path by default until another path selection is made The data file is comma delimited for easy use in other applications If a data file is created manually the Calibration Date CG and Beta values will be blank In this case it is critical that the molbloc have the same calibration coefficients during calibration activation as it did dur
49. species flowed in a calibration or verification test The gas with which the molbloc is being calibrated A test run by CalTool for molbloc that collects readings from a molbloc and a mass flow standard stores the readings in a data file dat and goes directly to the calculate and activate calibration functions at the end of the test Calibration tests are run with the intention of calculating new molbloc calibration coefficients Location of point A relative to point B in a flow system in which point A is at a different location in the direction of the flow For example the downstream molbloc pressure port is downstream relative to the upstream pressure port because it is at a different location from the upstream port in the direction of the flow DUT Full Mod Calibration Device Under Test The device being tested or calibrated A molbloc calibration option which is valid over a range of operating pressure Fixed Measurement Cycle Flow Standard A mass flow standard whose operating principle requires measurement of volume or pressure change over a period of time FS Abbreviation of full scale The full scale value is the maximum value or the span of a measurement range Limits and specifications are often expressed as FS Page 37 1999 DH Instruments Inc H CalTool for molbloc User s Manual Gauge K Factor Operating Pressure As in gauge pressure Pressure expressed
50. store files for molblocs However these restore files will return the molbloc to the calibration state last set by DHI Any subsequent calibrations performed with CalTool are be updated For this reason it is important to create restore files when multiple calibrations have been performed see Section 3 3 To load a restore file brs onto a molbloc select Tools Restore molbloc The lt Select molbloc Restore File gt window is presented Select the desired restore file brs and select lt Open gt CalTool requires several confirmations that the molbloc should really be restored with the identified restore file Following the restore operation View molbloc Calibration can be used to view the information on the molbloc s The Restore option should only be used when absolutely necessary Systematic restoring of the molbloc is not recommended 4 4 3 CREATE RESTORE FILE Create Restore File is used to create a molbloc restore file brs A molbloc restore file is a copy of the complete molbloc EEPROM contents that can be downloaded to the molbloc EEPROM using Restore molbloc see Section 4 4 2 To create a molbloc restore file brs select Tools Create Restore File After CalTool reads the molbloc contents through the test molbox the lt Save molbloc Restore File As gt window is presented Accept file name and path or edit it if desired Then select Save to create the restore file If any errors occu
51. tandard from test to test to quantify the repeatability of the system As a general rule the system repeatability should be 5 to 10 times better than the target measurement uncertainty for the molbloc 3 2 MANUAL CREATION OF A CALIBRATION DATA FILE To calculate new molbloc calibration coefficients and as left data CalTool for molbloc uses as received molbloc calibration coefficients and data contained in a dat file The dat file is created automatically by a Calibration or Verification Test run by CalTool Running a Calibration or Verification Test requires a live interface connection to a molbox If a molbox is not available to run a Calibration or Verification Test a data file dat can be created manually This feature allows CalTool for molbloc to calculate calibration coefficients and as left data using existing test data that was not recorded by CalTool or if an interface with the molbox cannot be established A valid interface with a molbox connected to the molbloc being calibrated is always required to calculate new calibration coefficients and or to activate new coefficients to the molbloc Use Data Create to create a calibration date file dat manually see Section 4 3 1 2 A valid data file must include the Reynolds number of the molbloc flow for every flow point When taking calibration test data manually to be entered later into CalTool be sure to record the Reynolds number of the molbloc flow at each point
52. the file on which calculations are to be performed must be specified The lt Select Data File gt window is presented Select the desired data file The Calculation function requires that valid communications with a molbox be set up and that the molbloc identified in the dat file selected is connected to the molbox If the information in the data file including the as received molbloc calibration coefficients for the gas specified in the data file does not match the molbloc that is connected the calculate process is aborted This feature is to assure that calculations are being performed for the correct molbloc with the correct calibration coefficients Ifthe molbloc coefficients are not the coefficients that were active when the data in the data file was taken the calculation of the new calibration coefficients and as left data would not be valid Page 19 1999 DH Instruments Inc CalTool for molbloc User s Manual If the information contained in the selected data file matches the current molbloc CalTool opens the lt Calculation Activation gt screen and calculates new as left molbloc calibration coefficients for the test gas and predicted as left data The as left data is the as received data recalculated using the new molbloc calibration coefficients At this point no changes have been made to the molbloc To make changes to the molbloc lt Activate Calibration gt must be selected Click lt Activate Calibration gt
53. w Data Print Current Text Display prints the contents of any open test display for example a formatted result file or a molbloc calibration record This function is useful for maintaining hard copy records of CalTool information The toolbar print option on the text viewer is a shortcut to this function 435 View allows result res and data dat files to be viewed within CalTool After selecting Data View select Result File or Data File to view the unformatted comma delimited file Select Formatted Result File Formatted Data File to view a file in a report style format that is more readable than the standard comma delimited format A print option on the viewer can be used to print the text display Page 25 1999 DH Instruments Inc CalTool for molbloc User s Manual 4 4 TOOLS MENU The Tools menu offers various tools to support the calibration and adjustment of molblocs with CalTool The Tools menu includes the following selections Remove Gas Calibration Restore molbloc Create Restore File View molbloc Calibration and Change molbloc Calibration Date 4 4 1 REMOVE GAS CALIBRATION Remove Gas Calibration allows undesired gas calibrations to be removed individually from a molbloc To remove the calibration of a gas from molbloc select Tools Remove Gas Calibration CalTool reads the contents of the connected molbloc through the test mol
54. x ready not ready indication to indicate when to take readings The stability setting is typically set to 0 005 FS s of the molbloc or less Note that the molbloc full scale flow depends on the molbloc size range the calibration gas and the calibration operating pressure See Section 6 to determine the molbloc flow range for the calibration gas and pressure O Select the calibration test gas in CalTool using Setup Test Gas The test gas must be the gas for which the molbloc is to be calibrated no surrogates or k factors are possible Enter the CalTool Calibration Test function using Calibration Calibration Test CalTool establishes communications with the molbox with which the PC is interfaced and reads the molbloc characteristics off the molbloc EEPROM If CalTool cannot communicate with the molbox or if the molbox is not connected to a valid molbloc an error message is displayed After reading the molbloc information the Reference Information window is displayed Enter information to identify the mass flow standard being used as a reference in the calibration This information will be included in the test data file After entry of the reference information the Test Pressure window is displayed Enter the value of molbloc upstream or downstream pressure that will be held constant through the test After entry of the test pressure the Run Screen and Test Data Entry windows are displayed see Secti
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