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Appendix C:  Gas Correction Factors for Commonly Used Pure Gases

77

Appendix C:  Gas Correction Factors for Commonly

Used Pure Gases

Table 12 lists the gas correction factors for some commonly used pure gases.  If the GCF for
your gas is not listed, or you are using a gas mixture, you must calculate the GCF.  Refer to Gas
Correction Factor
, page 47, for more information.

Gas Correction Factors for Pure Gases

GAS

SYMBOL

SPECIFIC HEAT, Cp

cal/goC

DENSITY

g/l @ 0oC

CONVERSION

FACTOR

Air

Ammonia

- - -

NH

3

0.240

0.492

1.293

0.760

1.00

0.73

Argon

Arsine

Boron Trichloride

Bromine

Ar

AsH

3

BCl

3

Br

2

0.1244

0.1167

0.1279

0.0539

1.782

3.478

5.227

7.130

1.391

0.67

0.41

0.81

Carbon Dioxide

Carbon Monoxide

Carbon Tetrachloride

Carbon Tetraflouride

(Freon - 14)

Chlorine

CO

2

CO

CCl

4

CF

4

Cl

2

0.2016

0.2488

0.1655

0.1654

0.1144

1.964

1.250

6.86

3.926

3.163

0.701

1.00

0.31

0.42

0.86

Chlorodifluoromethane

(Freon - 22)

Chloropentafluoroethane

(Freon - 115)

Chlorotrifluoromethane

(Freon - 13)

Cyanogen

Deuterium

CHClF

2

C

2

ClF

5

CClF

3

C

2

N

2

D

2

0.1544

0.164

0.153

0.2613

1.722

3.858

6.892

4.660

2.322

0.1799

0.46

0.24

0.38

0.61

1.00

Diborane

Dibromodifluoromethane

B

2

H

6

CBr

2

F

2

0.508

0.15

1.235

9.362

0.44

0.19

Dichlorodifluoromethane

(Freon - 12)

CCl

2

F

2

0.1432

5.395

0.35

Table 12:  Gas Correction Factors for Pure Gases

(Continued on next page)

Summary of Contents for 246C

Page 1: ...A 2 98 Instruction Manual MKS Type 246C Single Channel Power Supply Readout Six Shattuck Road Andover MA 01810 2449 800 227 8766 or 978 975 2350 Fax 978 975 0093 E mail mks mksinst com Web site http w...

Page 2: ...ser The foregoing shall constitute the exclusive and sole remedy of the purchaser for any breach by MKS of this warranty The purchaser before returning any equipment covered by this warranty which is...

Page 3: ...120715 P1 Rev A 2 98 MKS Type 246C Single Channel Power Supply Readout...

Page 4: ...ny form or by any means electronic or mechanical including photocopying and recording or by any information storage or retrieval system except as may be expressly permitted in writing by MKS Instrumen...

Page 5: ...isation 9 Symboles apparaissant sur l appareil 10 Mesures de s curit et mises en garde 11 Informaci n sobre seguridad 13 S mbolos usados en el manual de instrucciones 13 S mbolos que aparecen en la un...

Page 6: ...31 Fuses 31 Line Voltage 32 Connectors 33 Interface Connector J9 33 MFC Connector J8 34 Microjack Connectors 35 Chapter Three Overview 37 General Information 37 Flow Signal Path 37 Set Point Signal 3...

Page 7: ...r Gas Mixtures 49 Labels 51 Serial Number Label 51 Chapter Four Operation 53 How To Setup the System 53 Manual Flow Control 60 How To Manually Control Individual Gas Flows 60 How To Manually Control R...

Page 8: ...Voltage Reference 71 Digital Panel Meter 71 Set Point Buffer and Flow Switching Circuit 72 Appendix A Product Specifications 73 Appendix B Model Code Explanation 75 Model Code 75 Appendix C Gas Correc...

Page 9: ...10 Serial Number Label 51 Figure 11 Gauge Factor Scaling Control Potentiometer Example Setting 56 Figure 12 Fuse Holder Clip 68 Tables Table 1 Definition of Symbols Found on the Unit 2 Tabelle 2 Defin...

Page 10: ...List of Figures and Tables viii...

Page 11: ...ike which if not correctly performed or adhered to could result in injury to personnel Caution The CAUTION sign denotes a hazard It calls attention to an operating procedure practice or the like which...

Page 12: ...5019 Frame or chassis IEC 417 No 5020 Equipotentiality IEC 417 No 5021 Direct current IEC 417 No 5031 Alternating Current IEC 417 No 5032 Both direct and alternating Current IEC 417 No 5033 a Class ll...

Page 13: ...G THE PRODUCT This product is grounded through the grounding conductor of the power cord To avoid electrical shock plug the power cord into a properly wired receptacle before connecting it to the prod...

Page 14: ...t specified in the manual USE THE PROPER FUSE Use only a fuse of the correct type voltage rating and current rating as specified for your product DO NOT OPERATE IN EXPLOSIVE ATMOSPHERES To avoid explo...

Page 15: ...PI D Y WPIGP IGPFG GT EMUKEJVKIWPI W TRGTXGTNGV WPI H JTGP MCPP 8QTUKEJV Das Symbol VORSICHT weist auf eine Gefahrenquelle hin Es macht auf einen Bedienungsablauf eine Arbeitsweise oder eine sonstige...

Page 16: ...5017 Schutzleiter IEC 417 Nr 5019 Rahmen oder Chassis IEC 417 Nr 5020 quipotentialanschlu IEC 417 Nr 5021 Gleichstrom IEC 417 Nr 5031 Wechselstrom IEC 417 Nr 5032 Wechselstrom und Gleichstrom IEC 417...

Page 17: ...rch wird sicher gestellt da alle Sicherheitseinrichtungen voll funktionsf hig bleiben Wartung nur durch qualifizierte Fachleute Das Geh use des Instruments darf vom Bedienpersonal nicht ge ffnet werde...

Page 18: ...Netzkabel sollte einen Pr fvermerk einer zust ndigen Pr fstelle tragen z B VDE Semko oder SEV Richtige Stromquelle verwenden Dieses Produkt ist f r eine Stromquelle vorgesehen bei der die zwischen de...

Page 19: ...GUUWTG GP ECU F GZ EWVKQP KPEQTTGEVG QW FG PQP TGURGEV FGU EQPUKIPGU VVGPVKQP L indication ATTENTION signale un danger potentiel Elle est destin e attirer l attention sur une proc dure une utilisation...

Page 20: ...tection masse IEC 417 No 5019 Masse IEC 417 No 5020 Equipotentialit IEC 417 No 5021 Courant continu IEC 417 No 5031 Courant alternatif IEC 417 No 5032 Courant continu et alternatif IEC 417 No 5033 a M...

Page 21: ...ent des composants et les r glages internes doivent tre effectu s uniquement par un personnel d entretien qualifi MISE LA TERRE DE L APPAREIL Cet appareil est mis la terre l aide du fil de terre du co...

Page 22: ...n entre les conducteurs d alimentation ou entre les conducteurs d alimentation et le conducteur de terre sup rieure celle sp cifi e dans le manuel UTILISATION D UN FUSIBLE APPROPRI Utiliser uniquement...

Page 23: ...Q TGCNK CTUG W QDUGTXCTUG EQTTGEVCOGPVG RQFT C ECWUCT NGUKQPGU C NQU GORNGCFQU 2TGECWEK P El s mbolo de PRECAUCI N indica un riesgo Pone de relieve un procedimiento pr ctica etc de tipo operativo que...

Page 24: ...N 5017 Protecci n a tierra IEC 417 N 5019 Caja o chasis IEC 417 N 5020 Equipotencialidad IEC 417 N 5021 Corriente continua IEC 417 N 5031 Corriente alterna IEC 417 N 5032 Corriente continua y alterna...

Page 25: ...POR T CNICOS ESPECIALIZADOS Los operarios no deben retirar las cubiertas del instrumento El cambio de piezas y los reajustes internos deben efectuarlos nicamente t cnicos especializados PUESTA A TIER...

Page 26: ...ADECUADA Este instrumento debe funcionar a partir de una fuente de alimentaci n el ctrica que no aplique m s voltaje entre los conductores de suministro o entre uno de los conductores de suministro y...

Page 27: ...be used to monitor and provide a set point level for an MFC and to provide ratioed set points for multiple gas control The 246 unit is a versatile instrument that may be used separately or as part of...

Page 28: ...e instrument malfunction Appendix A Product Specifications lists the specifications of the instrument Appendix B Model Code Explanation describes the instrument s ordering code Appendix C Gas Correcti...

Page 29: ...ber Equipment Return Authorization Number from a MKS Service Center before shipping Please refer to the inside of the back cover of this manual for a list of MKS Calibration and Service Centers Cautio...

Page 30: ...lded cables properly grounded at both ends are required to meet CE specifications 2 To order metal braided shielded cables add an S after the cable type designation For example to order a standard cab...

Page 31: ...rnal wires exit 3 With very few exceptions the connector s must make good contact to the device s case ground Good contact is about 0 01 ohms and the ground should surround all wires Contact to ground...

Page 32: ...g Environmental Requirements Ambient Operating Temperature 15 to 40 C 59 to 104 F Main supply voltage fluctuations must not exceed 10 of the nominal voltage Ventilation requirements include sufficient...

Page 33: ...ensions are listed in inches with millimeters referenced in parentheses Window 1 0 1 0 3 0 20 4 0 50 6 0 70 8 0 90 3 375 85 7 3 469 88 1 Figure 1 Front Panel Dimensions Window 1 0 1 0 3 0 20 4 0 50 6...

Page 34: ...Setup Chapter Two Installation 24 12 12 307 9 Front Panel 0 125 3 175 Access to Internal Decimal Point Selector Dipswitches Cover Screws 4 each side Cover Figure 3 Side Panel Dimensions...

Page 35: ...or these accessories are listed in Unpacking Checklist page 19 However the unit is mounted leave adequate space around it for proper ventilation Refer to Dimensions page 23 for dimensional drawings of...

Page 36: ...nt panel SET POINT CONTROL which is connected to an internal 5 V reference Since the 5 V corresponds to full rated flow the SET POINT CONTROL can be adjusted up to a maximum of 100 of the rated flow f...

Page 37: ...master is controlled with its front panel SET POINT CONTROL which is connected to an internal 5 V reference Since the 5 V corresponds to full rated flow the master s SET POINT CONTROL can be adjusted...

Page 38: ...e system requires the 246 unit the MFC an external pressure controller and the appropriate cables To connect the 246 unit to an external controller connect the proper interface cable from the external...

Page 39: ...ave 246 Unit Channel 4 CB396S 1 2 Window 1 0 1 0 3 0 2 0 4 0 5 0 6 0 7 0 8 0 9 0 Window 1 0 1 0 3 0 2 0 4 0 5 0 6 0 7 0 8 0 9 0 Window 1 0 1 0 3 0 2 0 4 0 5 0 6 0 7 0 8 0 9 0 CB246S 2 3 Type 250 Contr...

Page 40: ...c control The MFC Interface connector J8 provides the means to remotely turn the flow on off and to adjust and monitor the flow rate using a set point signal from an external voltage Refer to Table 8...

Page 41: ...ses The line fuses protect the internal circuitry both sides of the line are fused The fuse values are listed in Table 6 Fuse Information Voltage Setting Fuse Type MKS Part Number 115 VAC 630 mA T 250...

Page 42: ...n the panel cutout Caution The Line Voltage Selector must be set to the proper input voltage before you connect the AC line cord Otherwise the unit will be severely damaged To set the line voltage 1 E...

Page 43: ...rn 2 0 to 1 V nominal Corrected Output Flow output corrected by rear panel Gauge Factor Scaling Control 3 Analog Return 4 Remote ON OFF Line used for an external remote control of flow controller Comp...

Page 44: ...applied here 3 No Connection 4 No Connection 5 Power Ground 6 15 Volts Supplied by the 246 unit 7 15 Volts Supplied by the 246 unit 8 Set Point Output Signal From the 246 unit to the MFC 9 No Connect...

Page 45: ...e connector J9 providing a 0 to 5 V sensor output voltage which is corrected by the front panel ZERO CONTROL Set Point In Out Connectors The Set Point In and Set Point Out jacks are internally connect...

Page 46: ...Connectors Chapter Two Installation 36 This page intentionally left blank...

Page 47: ...n signal if necessary using the front panel ZERO CONTROL This signal is sent to three places 1 To an output pin on Interface connector J9 This is a 0 to 5 Volt non gas corrected output This output is...

Page 48: ...al gas flows based on the 246 unit s Set Point or to ratio the gas flow from multiple 246 units to the flow from a master 246 unit A voltage signal from an external controller Use an external voltage...

Page 49: ...properly set Refer to Gauge Factor Scaling Control page 44 for more information Flow Control Switch This 3 position toggle switch controls the circuit which applies the set point signal to the MFC as...

Page 50: ...J9 This setting provides for the set point voltage to be the ratio of an external source where the ratio is set by the front panel Set Point Control EXT Position Selects the set point signal from a p...

Page 51: ...enter the scaling factor which scales down the 5 VDC transducer output signal so that the Digital Panel Meter displays the flow rate directly in sccm or slm Normally set to 1 00 it can be raised or lo...

Page 52: ...nnection to the scaled transducer outputs the lines to turn the flow on and off and the set point input lines which remotely set the flow rate of the MFC Refer to Table 7 page 33 for the Interface Con...

Page 53: ...AC line cord Otherwise the unit will be severely damaged Side Panel Control Decimal Point Selector Dipswitches This 4 position dipswitch located inside the unit on the edge of the Main PC board sets...

Page 54: ...n read up to 1999 counts it cannot be adjusted to the 5000 counts needed to accommodate the 5 VDC full scale output signals from the MFC Therefore the 5 VDC output voltage from the MFC must be scaled...

Page 55: ...500 50 500 sccm 1000 100 1000 sccm 2000 200 1999 sccm 5000 50 5 00 slm 10000 100 10 00 slm 20000 200 19 99 slm 50000 50 50 0 slm Table 9 MFC Gauge Factors Gas Correction Factor A Gas Correction Factor...

Page 56: ...turned below 0 or above the full scale setting of 1000 Note The maximum number of counts the meter can read is 1999 therefore the voltage cannot exceed 2 VDC Ensure that the scaling control potentiom...

Page 57: ...late its GCF The equations for calculating gas correction factors are listed in How To Calculate the GCF for Pure Gases page 48 and How To Calculate the GCF for Gas Mixtures page 49 The equations for...

Page 58: ...106 s d cp x x x where GCFx Gas Correction Factor for gas X 0 3106 Standard Density of nitrogen Specific Heat of nitrogen s Molecular Structure correction factor where S equals 1 030 for Monatomic gas...

Page 59: ...of nitrogen Specific Heat of nitrogen a1 through an Fractional Flow of gases 1 through n Note a1 through an must add up to 1 0 s1 through sn Molecular Structure correction factor for gases 1 through...

Page 60: ...nd nitrogen gas 2 flowing at 50 sccm where Argon Ar Nitrogen N2 a1 150 0 75 a2 50 0 25 200 200 s1 1 030 s2 1 000 d1 1 782 g l d2 1 250 g l cp1 0 1244 cal g C cp2 0 2485 cal g C then GCFM 0 3106 0 75 1...

Page 61: ...ber Label located on the side of the instrument lists the serial number and the product model code and displays the CE mark signifying compliance with the European CE regulations Serial Model MKS Inst...

Page 62: ...Labels Chapter Three Overview 52 This page intentionally left blank...

Page 63: ...the unit by connecting the AC LINE CORD and check that the DIGITAL PANEL METER on the 246 unit reads 000 1 count For protective earthing plug the power cord into a properly grounded outlet Caution The...

Page 64: ...Scaling Control page 44 for more information a The Scaling Control Factor is the product of the Gauge Factor for the MFC in use and the Gas Correction Factor for the gas in use SCALING CONTROL FACTOR...

Page 65: ...n gas multiply the Gauge Factor for argon 200 listed in Table 9 page 45 times the Gas Correction Factor for argon 1 39 listed in Table 12 page 77 SCALING CONTROL FACTOR GAUGE FACTOR x GAS CORRECTION F...

Page 66: ...ath the window The adjustment knob cannot be turned below 0 or above the full scale setting of 1000 To adjust the Scaling Control Potentiometer to the setting of 278 calculated in the example in step...

Page 67: ...ONTROL setting is calculated as follows based on the desired set point level as a percentage of full scale and the GCF for the gas in use SET POINT CONTROL SETTING of FS x 10 GAS CORRECTION FACTOR Exa...

Page 68: ...east 15 minutes Caution The 246 unit uses the AC line cord as its power switch that is the unit is ALWAYS ON when connected to a line source Note Allow a minimum of 1 hours for the MFC to reach contro...

Page 69: ...offset using the ZERO CONTROL on the 246 unit If you are unable to adjust the zero use the Zero Control pot on the MFC 12 Ensure that the unit s front panel FLOW CONTROL SWITCH is in the OFF position...

Page 70: ...ws based on the unit s internal 5 V set point signal 1 Set the SET POINT SOURCE SWITCH to the FLOW position This connects an internal 5 V reference to the top of the SET POINT CONTROL Since the 5 V co...

Page 71: ...o the top of the SET POINT CONTROL Since the 5 V corresponds to full rated flow each Set Point Control can be adjusted up to a maximum of 100 for the attached MFCs rated flow 2 Ensure that the SET POI...

Page 72: ...d is routed by the SET POINT SOURCE SWITCH to the MFC 1 Calculate and apply the external set point voltage for the MFC in use The external set point voltage is calculated as follows based on the desir...

Page 73: ...ECTOR SWITCH on the 250 controller is set to the proper voltage Note The 246 unit can operate with any controller or pressure transducer provided the signal that enters the 246 unit goes positive with...

Page 74: ...e units and the desired pressure within a factor of 2 in the chamber 7 Turn the flow ON by placing the FLOW CONTROL SWITCH on each 246 unit to the ON position The set point signal is applied to the MF...

Page 75: ...e Although the total flow rate will change the ratio between the gases will remain constant 10 Adjust the controller s GAIN and PHASE LEAD settings as needed The controller settings listed in Table 11...

Page 76: ...9 pinout When the FLOW CONTROL SWITCH refer to Figure 7 page 39 is placed in the REMOTE position a logic signal coming in through the Interface connector J9 may be used to gate the set point signal to...

Page 77: ...fer to the inside back cover of this manual for a list of MKS Calibration and Service Centers Maintenance Periodically check for wear on the cables and inspect the enclosure for visible signs of damag...

Page 78: ...ion of the fuse holder clip Fuse Holder Clip Figure 12 Fuse Holder Clip 5 Gerntly press against the clip and push up with the screwdriver until the plastic fuse holder pops out It may be necessary to...

Page 79: ...be within the range of 14 8 and 15 2 Volts and the AC ripple should be 10 mV P P If the voltages are within range proceed to step 4 If the voltages are not within the acceptable range proceed to step...

Page 80: ...W and the FLOW CONTROL SWITCH to ON The DVM should read approximately 5 Volts on pin 10 in connector J8 and on pin 6 in connector J9 To check the output of the ZERO CONTROL 1 Verify that the ZERO CONT...

Page 81: ...ed by a 5 V supply located on the Main PC board To measure the supply voltage to the meter 1 Measure the output of pin 2 in Interface connector J9 The voltage on the DPM should match the voltmeter rea...

Page 82: ...ctly If not suspect either U7 or possibly Q2 With no REMOTE ON OFF signal and either OFF or REMOTE selected on switch S2 the voltage on the gate of Q2 should be approximately 15 V and the drain voltag...

Page 83: ...Flow Display 3 Digit Display 1 999 maximum 0 56 Red LED display Fuse Ratings 115 VAC 230 VAC 630 mA T 250 V 315 mA T 250 V Operating Temperature 15 to 40 C 59 to 104 F Power Consumption 70 VA maximum...

Page 84: ...Signal Outputs MFC Output s Unscaled Uncorrected Transducer MFC Output Scaled Corrected Transducer MFC Output Minimum load impedance 10K ohm channel 0 to 5 VDC 0 to 1 VDC Nominal scaled with a rear p...

Page 85: ...odel Code 75 Appendix B Model Code Explanation Model Code The model code for the 246 single channel power supply readout is identified as follows 246C Type Number 246C The type number 246C designates...

Page 86: ...Model Code Appendix B Model Code Explanation 76 This page intentionally left blank...

Page 87: ...ride Bromine Ar AsH3 BCl3 Br2 0 1244 0 1167 0 1279 0 0539 1 782 3 478 5 227 7 130 1 391 0 67 0 41 0 81 Carbon Dioxide Carbon Monoxide Carbon Tetrachloride Carbon Tetraflouride Freon 14 Chlorine CO2 CO...

Page 88: ...2 0 43 0 22 0 50 Fluorine Fluoroform Freon 23 Freon 11 Freon 12 Freon 13 F2 CHF3 CCl3 F CCl2 F2 CClF3 0 1873 0 176 0 1357 0 1432 0 153 1 695 3 127 6 129 5 395 4 660 0 98 0 50 0 33 0 35 0 38 Freon 13 B...

Page 89: ...21 0 1373 0 246 0 2328 0 2485 1 518 9 366 0 900 1 339 1 250 0 56 0 21 1 46 0 99 1 00 Nitrogen Dioxide Nitrogen Trifluoride Nitrous Oxide Octafluorocyclobutane Freon C318 Oxygen NO2 NF3 N2 O C4 F8 O2 0...

Page 90: ...0 1592 0 1357 0 1380 0 161 0 0810 0 0378 6 516 6 129 6 043 8 360 13 28 5 858 0 26 0 33 0 33 0 20 0 25 1 32 1Empirically defined 2Consult MKS Instruments Inc for special applications 3The GCF for Oxyg...

Page 91: ...9 40 Fuses 31 42 replacement 67 G Gas correction factors 77 80 description of 45 47 gas mixtures 49 pure gases 48 reference temperature 47 Gauge factors 45 54 Grounding 31 I Installation Category 22 L...

Page 92: ...or 45 54 scaling control potentiometer 41 46 56 Serial number label 51 Set point control 40 signal 38 source switch 40 Setup external set point control individual gas flows 28 ratio gas flows 29 manua...

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