Qualiflow AFC-202 Mass Flow Controller Manual
Contents
1. Valve Configuration N for No valve only for AFM O for Advanced Flow Controller Normally Open C for Advanced Flow Controller Normally Close s Seals V for Viton N for Neoprene K for Kalrez M for Metal f f Inlet and Outlet Fittings SB for B SEAL SC for C SEAL SW for W SEAL SZ for Z SEAL Or specify first Inlet then Outlet F for 1 4 VCR Female B for Swagelok 1 8 M for 1 4 VCR Male C for Swagelok 1 4 L for 1 4 VCR High Flow Male G for Swagelok 6mm N for 1 4 VCR High Flow Female H for Swagelok 3 8 D for 3 8 VCR Female K for 1 8 BSPP AFM 10 only E for 3 8 VCR Male r r r r Flow rate Specify C for sccm L for sim Example 200C for 200 sccm 030L for 30 sim 9 9 9 Gas Process See chart on the left page m Mounting Position H for Horizontal U for Vertical Inlet Up D for Vertical Inlet Down 0 o Options AFC 260 AFC 261 AFC 202 AFC 50 AFC 70 80 90 AFM 360 AFM 361 AFM 302 AFM 55 AFM 10 AFM 85 95 L for Low Delta Pressure 2 i y v v S for Separated Electronics v v v Y E for External Readout D for Digital Card If Digital N for DeviceNet R for RS485 MODBUS x for nb of calibr curves 61 for AFC 50 compatible AFC 261 R d j i P for Special Pitch v v v v v Y y T2. nuts 123 123 83 5 83 5 2 2 1 INSTALLATION WARNING Toxic corrosive or explosive gases must be handled with extreme care After installing the mass flow controller the system should be thoroughly checked to ensure it is leak free Purge the mass flow controller with a dry inert gas for one hour before using corrosive gases IMPORTANT When installing the mass flow controller ensure that the arrow on the back of the unit shows the same direction as the gas flow 2 2 1 1 VCR COMPATIBLE COUPLINGS The AFC 202 mass flow controller is normally supplied with 1 4 male VCR compatible couplings on both sides To install the AFC follow the steps listed below 1 2 3 SOP Check the gland to gland space including the gaskets Remove the plastic gland protector caps a When using loose VCR original style gaskets insert the gasket into the female nut b For VCR retainer gaskets snap the gasket onto the male coupling See figure below Tighten the nuts finger tight Scribe both nut and body in order to mark the position of the nut While holding the body with a wrench tighten the nut 1 8 turn past finger tight for 316L stainless steel and nickel gaskets AFC 202 User s Manual D 10 032 VOO VCR retainer gasket VCR compatible couplings 2 3 ELECTRICAL INSTALLATION 2 3 0 GENERAL Within this section you will find the following sub sections e Connections e
3. proportional to the differential pressure between inlet and outlet of the tube F T R a p P nT up down p Volumic mass of the gas n Viscosity of the gas I length of the tube R radius of the tube So when a sensor tube radius Rs length Is and a bypass tube are in parallel radius Rb length Ib the flow in the sensor tube is proportional to the flow in the bypass _ R ls AR a However this is true only if the flow is laminar so if the tube are small enough This is way bypass are made by several thin tube instead of only one tube It is important to notice that a mass flow meter or controller measure the flow thru the sensor which is not the total flow but only one part of the flow split by the bypass according to last equation In this eguation radius of the sensor tube and bypass tube is at power 4 Conseguently any deposition in one of the tube changing the diameter will change the accuracy of the measurement Also because of the need to have a laminar flow bypass tube and sensor tube may have clogging This why mass flow meter and controller must be used with clean filtered gases CONTROL PRINCIPLES The electronic compares the amplified mass flow rate value measured by the sensor to the desired set point This comparison generates an error signal that feeds the regulating valve The difference is used to drive the control valve The control valve will proportionally open or close until the output is egual
4. Remove the 4 screws 9 in the top of the top housing 24 which hold the top ring assy 29 Then remove the bushing 32 AFC 202 User s Manual 15 D 10 032 VOO Note If o rings are dirty cut or cracked they have to be exchanged with appropriate new clean ones 4 1 1 ASSEMBLY PROCEDURE First mount sensor inlet and outlet fittings Caution The sensor capillary sometimes extends beyond the seals o rings When positioned on the base without verifying that capillary ends fit in the holes in the base the capillary can be bend or damaged Therefore center the sensor by means of the mounting screws hold it up and then fasten the screws Normally open valve 1 Check the quality of the contact between 3 8 ball and its seat on top housing 24 Both parts should be polished without any scratch Place upper bellow 40 in top housing 24 3 Select number of washers M3 crown spring 30 and ball so that the end of the stem of the upper bellow assy is 1 to 1 5 mm below top surface of the top housing with ball on the seat 4 Select now place of the crown spring between the washers so that when the crown spring is on its seat the ball is lifted halfway the space adjusted in step 3 0 5 to 0 75 mm Note keep ball washers and crown spring together with nut M3 5 Now lengthen carefully the upper bellow so that it just contact the crown spring 6 Mounting assy in top housing 7 Place spring 6 over the upper bellow Add spring adjustment ri
5. VOO SECTION 5 TROUBLESHOOTING 5 0 INITIAL CHECK 1 Check the set up and procedure against installation instructions Permanent damage to the unit may result if purging procedures are not followed or if a line power is accidentally applied to the signal leads 2 Test line cord for compliance with pin assignment and continuity from all wires to correct pins Use hipot tester to check for any pin to pin shorts during this test flex the cable coming out of the connector to find intermittent shorts 3 Check insulation resistance from pins to base All except pin 1 should exceed 50 MQ at 50 VDC Pin 1 to base should measure less than 1 O 5 1 SYMPTOMS No output Faulty meter Read output at pins 3 and 2 directly with alternate meter No actual Flow Check pressure valve positions line or filter blockage Sensor clogged Follow Sensor Cleaning Maintenance Valve closed Follow Valve Cleaning Maintenance Electronics failure See below Faulty power supply Check input output voltages 15VDC 5VDC Maximum signal between Check valve voltage as measured across 150 and 200 of full valve lead wires Valve should close scale when voltage rises to 14 Volt for normally open and valve should open when a Indication correct flow is Valve defective voltage rises to 14 volt for normally close high b Indication erroneous Open resistance on sensor Replace sensor element Electronics failure See below Signal offset at zer
6. anne Esel 7 2 0 INTRODUCTION u ee nenne 7 2E UNPACKING iA YF GY UA FO aia 7 2 2 SMECHANIEREINSTALERTION Eee a ne a at 7 2 2 0 GENERA let Eu ee NER 7 2 2 NR E RE NEE 8 2 3 EEBCTRICAL INSTALEATION strain 9 230 GENERAL ati RT io dad ad 9 2 3 1 CONNECHONS sa Ed 9 2A CHECKS BEFORE STARTING UP siii ii id 10 SECTION S ADIESTEMENT anna ee 11 30 REQUIRED FACILITIES as bane eu 11 Ss APOFENTIOMETERSADIUNTMENT Lungene eda a 11 32 NALVEADJIUSIMENT ege ale ae 13 42 0 NORMALLY OPEN VALV E ae 13 Ao A NORMALLY CEOSE VALVE porsi ianh see aa 13 3 3 CHANGE OF CALIBRATION susanne rer 14 3 3 O NORMALES OPEN GAN hue Heu 14 3 3 1 NORMALLY CLOSE VALVE Aus iii ds 14 34 DYNAMIC RESPONSE ADJUSTMENT s 000000s005050000 nes 14 SECTION 4 MAINTENANCE spe ee ia 15 4 0 GENERAL nd a u raden 15 4 1 DISASSEMBLY AND ASSEMBLY PROCEDURES AAA 15 41 0 DISASSEMBLY PROCEDURE envia 15 41 1 ASSEMBEY PROCEDURE isnende 16 4 2 SENSOR CLEANING AND REPLACEMENT 2022000220240002200nnsnnenonnnonennnnn 18 4 2 VALVE CLEANING AND REPLACEMENT meirronoovvrnennvareenvenesennaneennnnserneneennaneennene 18 SECTIONS TROUBEESHOOTING usa euere 19 50 INITIAEC HEER coda 19 SMP ONS sa are 19 SECTION 6 WARRANTY AND SERVICES u u euesen cn een 20 6 0 PRODUCT WARRANTY sintio aba ah rn 20 Gr SER NES 21 APPENDIX A PART NUMBER DESCHRIDTION ENNEN 22 APPENDIX BR GAS PROCESS NUMBER ne usu en sen 23 APPENDIX C EXPLODED VIEW OF THE AFC 202
7. follows i The system must be wired carefully non observance of the pinout may irreversibly damage the electronic board inside the MFC in which case the warranty will be invalidated ii A stable power supply is required with ripple below 5mV d Gas connections the VCR gland must be handled carefully Qualiflow guarantees that all glands have been individually inspected and are scratch free e Fitting procedure the fitting procedure set out in the manual must be followed meticulously Specifically the purge procedure is very important if corrosive gases or toxic gases are used f The mass flow must not be dismounted the MFC warranty will be invalidated if the seal between the MFC block and cover is torn 6 1 SERVICES QUALIFLOW Products Engineers will help you to solve your problems regarding operation calibration connection gas flows gas mixture etc We deliver technical support or maintenance within 24 hours QUALIFLOW offers factory training on mass flow controllers Visit www qualiflow com and find your nearest repair and calibration center AFC 202 User s Manual 21 D 10 032 V00 APPENDIX A PART NUMBER DESCRIPTION tbtt L v s f f r r r r g g g lm o o t Type gel 100 for AFM 10 260 for AFC 260 or AFM 360 261 for AFC 261 or AFM 361 202 for AFC 202 or AFM 302 500 for AFC 50 or AFM 55 700 for AFC 70 800 for AFC 80 or AFM 85 900 for AFC 90 or AFM 95 v
8. to the setpoint Note that valve can be normally open or normally close This is the position that will have the valve when the mass flow is not connected on power supply The valve can be actuated by a magnetic solenoid Then it can be normally open or normally close and response time of the valve itself is almost instantaneous In practise response time of the mass flow controller is limited by the response time of the sensor As sensor is based on thermal exchange it takes 1 to 5 s for the sensor to measure a gas change Several technigues allows to increase this response time and allow to get on the best mass flow response time bellow 5s The valve can be also made by a heating wire which heat a small tube then dilation will move a ball at the end of the tube This kind of valve can be only normally open and is guite slow Mass flow controller using such valve will have response time around 5 to 6 s for flow bellow 5 sim and up to 10 s for flow up to 5 sim However this technology is simple and reliable and can be recommend for many low cost application when response time is not critical AFC 202 User s Manual 30 D 10 032 VOO
9. to the unit i e ask to the unit to regulate at 100 of the full scale Then look at the readout given by the reference flow and compare it to Vie Previously calculated if the readout given by the reference flow Mr the gain is well calibrated if the readout given by the reference flow is slightly different from Vier difference is less than 3 of Vier the full scale adjustment can be done electronically only with the the gain potentiometer Go to step 11 if the readout given by the reference flow is very different from Vier difference is more than 3 of Vier the bypass need to be adjusted before any electronic adjustment go to next step 7 Previously to adjust the bypass put the linear potentiometer and the gain potentiometer to half of their stroke both potentiometers are 15 turns models 8 Adjust the bypass 9 First remove the inlet fitting with a 1 wrench to access the bypass the bypass is a preadjusted assembly which can be removed and reinstalled with the use of a screwdriver It consist of a stainless steel grid cylindrical net with a Kel f plug inside By adjusting the position of the kel f plug the grid allow less or more the flowing of the gas AFC 202 User s Manual 12 D 10 032 VOO 10 11 13 14 15 16 17 3 2 4 2 0 Adjust the bypass by pushing the Kel f plug inside the bypass if the ref flow is lower than the full scale of the unit Or you need to pull the Kel f plug insi
10. 6 02 Oxygen 015 1 429 0 2183 0 996 03 Ozone 030 PH3 Phosphine 031 1 523 0 2607 0 688 C3H8 Propane 089 1 98 0 392 0 35 SiH4 Silane 039 1 438 0 3188 0 596 SiF4 Silicon Tetrafluoride 088 4 68 0 168 0 35 Si2H6 Disilane 097 SO2 Sulphur Dioxide 032 2 91 0 149 0 67 SF6 Sulphur Hexafluoride 110 6 5 0 1590 0 27 TiCl4 Titanium Tetrachloride 114 8 465 0 22 0 30 C4F8 Octafluorocyclodutane 129 SiHCI3 Trichlorosilane 147 6 047 0 130 0 348 AFC 202 User s Manual 23 D 10 032 VOO APPENDIX C EXPLODED VIEW OF THE AFC 202 D 10 032 VOO 24 AFC 202 User s Manual e lr Spring 800100204 7 1 Finder Ming 38 sw A eii 8 aso Outlet fitting 3 8 sw 500210005 sa i outer iting 38 VOR s0001 1203 Screw M3x8 hex head C en 10A 1 Fitting plate assy AFM302VCR_ TI IL IL O ring25x2 Viton 14 2 ScrewsM3x16panhead 15 2 ScrewsM3x10Hexhead 16 1 ScrewsM3x5panhead 17 2 Screws M4x10hexhead 18 4 ScrewsMSx10hexhead 20 1 Sticker name plate 21 Sticker gas range amp SN 1 22 1 Sticker pin assignment 25 Jr Magnet actuator Normaly Open 500600001 NO 25A 1 Magnet actuator Normaly Close 500600001 NC O ring 20x2 Viton 808092043 Tv meme 33 ScrewM3x5panhead 35 4 screwM5x50hexhead 36A 0 Donotuseonnormaly close a Ju mM AFC 202 User s Manual 25 D 10 032 VOO APPENDIX D GENERAL MFC PRINCIPLES Mass Flow Contro
11. Pressure control e Ratio control 2 3 1 CONNECTIONS The AFC 202 includes a cardedge connector 1 Case Ground A Control Input 0 1 5 VDC AFC 202 only KKK 2 Common B Common valve AFC 202 User s Manual 9 D 10 032 VOO 3 Output O 5 VDC C Common 4 15 VDC D Valve test point Soft start connection 6 Zener Test Point F 15 VDC 7 J Sensor Up stream 8 K Sensor Common 9 L Sensor Downstream 10 Extra Output Notes 1 Soft start connection 2 Not available in earlier PC boards 3 Valve common is jumpered to C Remove this jumper J 3 and use separate common is advise every time it is possible 4 Any DC voltmeter or recorder can be used to visualize the output signal Input impedance should be at least 5000 ohms 5 The control Input signal should be from any voltage source with maximum impedance 2500 ohms 2 4 CHECKS BEFORE STARTING UP Before operating the mass flow controller the following checks should be completed 1 2 3 4 5 Check that tubing is leak proof Check the process sequence and proper function of all other gas components involved Check the voltage of command signals and power supply to the mass flow controller Check that the appropriate gas type is being supplied at the rated pressure Allow the mass flow controller to warm up for 20 minutes then check the zero level output Use dry inert gas for test runs Prior to using the mass flow controller for extre
12. ars for 30 sim 2 bars for 50 sim 2 5 bars for 100 sim and 3 bars for a 200 sim full scale Adjust screw until desired flow is reached Lock with nut NORMALLY CLOSE VALVE There is normally few external valve adjustment necessary on the normally close version however 1 Connect the unit to gas supply Adjust setpoint to 5 00 V 100 full scale Apply inlet gas pressure to maximum working pressure required for application Check that the power supply of the valve when flow is stable is between 8 and 10 V Switch of the gas Remove screws 41 magnet 25A AFC 202 User s Manual 13 D 10 032 VOO Adjust the spring 6 by turning ring 31 across the crown spring of the top ring 29 Put magnet 25A then screw the threaded rods 39 and nuts 41 Apply inlet gas pressure to maximum working pressure required for application om na o Check that the power supply of the valve when flow is stable is between 8 and 10 V If not come back to step 5 Connect a reference flow meter before the unit eo TN Remove electrical connector 9 Check the valve closing is good less than 2 of the flow ie less than 100 mV on the readout of the reference flow meter If not disassemble the valve and assemble it again 10 If the magnet step 6 or the whole valve step12 have been dismounted leak test must be performed 3 3 CHANGE OF CALIBRATION 3 3 0 NORMALLY OPEN VALVE Follow 4 3 Valve adjustment then 4 2 Potentiometers adjust
13. cedure then test the valve 17 Do final leak test Normally close valve 1 Check the quality of the contact between 3 8 ball and its seat on top housing 24A Both parts should be polished without any scratch 2 Place upper bellow 40 in top housing 24A and adjust bellow by pulling or pushing so that the top of the upper bellow stem 40 is adjusted to the top of the housing 24A 3 Remove upper bellow 40 Place washers M3 27 over stem and place crown spring 30 Add washers that crown spring 30 just touches the bottom of the bellow assy 0 5 mm Normal value 3 washers of 0 8 mm 5 Place the assy 40 up side down in top housing 24 and put on solid surface seat up Now place ball over the stem from 40 with ball O ring grove faced to the seat Look for contacting ball to seat And measure the exposed end of M3 from the stem length is A 6 Disassemble again Place now the ball 29 over the stem same way as above and screw a M3 nut on the stem Adjust nut to the same dimension as A Measure space B between crown spring and ball Disassemble ball and nut M3 Prepare a package of small washes M3 27 to a thickness B Normal value 6 washers of 0 8 mm May be necessary to put 5 0 8mm 1 0 5mm or 5 0 8mm 2 0 5mm 9 Mounting assy in top housing 10 Place spring 6 over the upper bellow Add spring adjustment ring 31 screw these over half way the thread length 11 Place the O ring 26 over the upper bellow and put in place in th
14. de the bypass if the ref flow is higher than the full scale of the unit To push the bypass just push the plug slowly with a special tool and a hammer 12 To pull the bypass dismount the bypass with a screw driver and push the plug by the backside Assemble again the bypass the inlet fitting in the gas line and come back to step 7 Turn the gain potentiometer until you get Vier on the readout of the reference flow meter If you can not get the Vref on the readout of the reference flow meter than the bypass need to be readjusted come back to step 8 Linearity adjustment Apply a 2 50 VDC setpoint to the unit i e ask to the unit to regulate at 50 of the full scale Then look at the readout given by the reference flow and compare it to half of V e calculated at step 6 The readout of the reference flow meter should be equal to half of Vier If not adjust the LINEARITY potentiometer R29 to get half of Ve on the readout of the reference flow meter Check again the ZERO as explained in step 3 the gain potentiometer as explained in step 11 and the linearity potentiometer as explained in step 12 Check the 3 potentiometers neither of the 3 need to be adjusted VALVE ADJUSTMENT NORMALLY OPEN VALVE In this valve version there is a screw and a locknut on the top of the magnet Adjustment 1 2 3 4 4 2 1 Remove electrical connector Connect a reference flow meter before the unit Apply inlet gas pressure to 1 5 b
15. delivered with a normally open or normally closed valve Fast and smooth control is secured by appropriate feed back and speed up arrangements Both units have the same rigid small housing which is particularly suitable for compact rational built gas systems the more so as they can be mounted in any position 1 1 AFC 202 USER s MANUAL This manual includes the following sections Section 1 Introduction contains specifications and calibration features Section 2 Installation contains all the information necessary to unpack the AFC 202 without causing contamination install the AFC 202 and check the installation before starting up Section 3 Adjustment Section 4 Maintenance Section 5 Trouble shooting 1 2 SPECIFICATIONS AFC 202 Input 15VDC 5 25mA 15VDC 5 180mA Setpoint Signal 0 1 5 VDC Output Signal O 5 VDC Respons time typ 4s AFC 202 User s Manual 5 D 10 032 VOO 5 40 C Minimum differential 1 5 bar for 30 sim F S gas pressure 2 bar for 50 sim F S 2 5 bar for 100 sim F S 3 bar for 200 sim F S Pressure 0 1 atm typ Coefficient Leak Rate lt 2 10 scc sec Specifications values Note AFC and AFM are delivered with viton seals except NH3 mass flow which are delivered with neoprene seals Please contact your local representative for other kind of seal material 1 3 CALIBRATION FEATURES The Mass Flow Controllers are calibrated close to customer s process Witho
16. e top housing Caution The O ring 26 must be very clean clean with alcohol if necessary without any scratch Same think for its chamber in the top housing If not very small leak may occur and with time full the top housing with high pressure with consequence that the valve will stay permanently in open position 12 Place package washers B O ring 28 and the ball over the stem and place M 3 nut to prevent dropping of the parts 13 Place bushing 32 topring assy 29 and the 4 M3 screws 9 do not yet tight 14 Preparing lower bellow assy Be assured there is no gap between bellow and the part screwed at the bottom Unscrew and counter sunk the bellow part as necessary 15 Now screw and tighten the lower bellow to the stem coming out the top housing remove first the M3 nut putted during step 12 16 Adjust the lower bellow at 47 5mm as when it will be mounted into the housing 23 it should not be compressed or extended AFC 202 User s Manual 17 D 10 032 VOO 17 Assemble top housing to the housing 23 with O ring 27 on bellow assy and O rings 36 38 but without magnet in place for first leak test of O ring 26 Do not forget the snap ring on the top of the upper bellow stem 40 18 Assemble top housing with magnet in place Do not Install the O rings 36 with inert gas 19 Test valve 20 Do final leak test Note For leak testing of the AFC 202 normally close it is necessary to put power on it to open the valve or pumping down f
17. ed electrically to 80 C above the ambient temperature When the gas is flowing the upstream region cools down whereas the downstream region heats up causing a temperature gradient along the length of the tube see the sensor temperature profile figure AFC 202 User s Manual 27 D 10 032 V00 2 Winded Resistances Hy me Sensor tube Flow in gt TEMPERATURE NO FLOW Sensor tube Flow in gt gt mW R R R R SR 1 O sccm 2 Winded Resistances Sensor temperature profile The coils of the heating resistances are made with a thermal sensitive wire so that the temperature differences due to the flow are directly converted into resistances change Those resistance change are convert in voltage by a simple wheatston bridge working zone Sensor measurment 5 sccm Gaz Flow sensor response For flow under 5 sccm the measurement is proportional to the flow with a coefficient which depends on p Volumic mass of the gas Cp specific heat for a constant pressure AFC 202 User s Manual 28 D 10 032 VOO N spin factor Constant which depend of the molecular structure of the gas and compensates for the temperature dependence of Cp Value of N Monoatomic gas 1 04 Diatomic gas 1 00 Triatomic gas 94 Polyatomic gas 88 For flow higher then 5 sccm the sensor is first non linear then the measurement starts to decrease with flow because the gas flow is too fas
18. event heating up of the magnet with zero setpoint Caution Be careful to avoid contact between the valve connector and the sensor connector close to the zero potentiometer This will destroy the transistor BC107B When this transistor is damaged the readout stay at the same value even with gas flow 4 Apply gas to the inlet fitting and put the reference flowmeter in series If your reference flow meter is a flow controller you need to let the valve fully open for that disconnect the valve wires of your reference flowmeter if it is a normally open valve or connect pin C and D of your reference flowmeter if is a normally close valve 5 Calculate Vref at full scale Cs F i V ef unit 5 00 C unit ref Where Crer is the conversion factor of the calibration gas Cunit is the conversion factor of the gas that the unit will control F unit is the full scale value of the unit Fer is the full scale value of the reference flow meter AFC 202 User s Manual 11 D 10 032 VOO Example 1 complicated Unit to calibrate 30 slm Oxygen Reference flow meter 50 sim Nitrogen calibration gas Nitrogen Cre 1 Cunit 0 996 Funit 30 slm Frer 50 sim then Vier 3 012 V Example 2 simple Unit to calibrate 200 slm nitrogen Reference flow meter 200 sim Nitrogen calibration gas Nitrogen Cer 1 Cunit 1 Funit 200 sim Fret 200 sim then Vie 5 00 V 6 Full scale adjustment Apply a 5 00 VDC setpoint
19. for Low Temperature Sensitivity a 3 e v A for High Accuracy B for Brass body C for Signal 4 to 20 mA M for Power Supply 24 VDC v v Standard v v lt lt lt lt lt lt lt 6 6 lt lt lt Er en a lt lt lt Q KNE EG lt lt lt 066 v SS SS 4 lt lt 6 SS SS 65 lt lt lt lt AFC 202 User s Manual 22 D 10 032 VOO APPENDIX B GAS PROCESS NUMBER Symbol Gas Name Number Density Sp Heat C SEMI E52 cal g C 0298 Air 008 1 2929 0 2401 1 000 NH3 Ammonia 029 0 7710 0 519 0 68 Ar Argon 004 1 7842 0 1246 1 453 AsH3 Arsine 035 3 481 0 1178 0 666 BCI3 Boron Trichloride 070 5 26 0 130 0 40 CO Carbon Monoxide 009 1 2500 0 495 1 000 CCI4 Carbon Tetrafluoride 101 6 86 0 141 0 309 CI2 Chlorine 019 3 209 0 116 0 83 B2H6 Dibirane 058 1 24 0 495 0 44 SiH2CI2 Dichlorosilane 067 4 54 0 141 0 43 CHF3 Fluoroform 049 3 125 0 173 0 506 CCI2F2 Freon 12 084 5 5 0 149 0 34 CF4 Freon 14 063 3 96 0 167 0 41 GeH4 Germane 043 3 423 0 138 0 58 He Helium 001 0 1788 1 242 1 454 H2 Hydrogen 007 0 0899 3 400 1 016 HCI Hydrogen Chloride 011 1 635 0 1937 0 981 C2F6 Hexafluoroethane 118 6 16 0 185 0 24 Kr Krypton 005 3 73 0 0596 1 45 CH4 Methane 028 0 7166 0 528 0 722 CH3SiCI3 Methyltrichlorosilane 183 6 670 0 164 0 250 N2 Nitrogen 013 1 2503 0 2484 1 000 NO2 Nitrogen Dioxide 026 6 675 0 194 0 41 NF3 Nitrogen Trifluoride 053 3 173 0 178 0 434 N20 Nitrous Oxide 027 1 98 0 206 0 20
20. hecks in the troubleshooting section as it may not be necessary to dismantle the valve Prior to disassembly make sure the unit has been purged with a dry inert gas WARNING if it becomes necessary to remove the controller from the system after exposure to toxic pyrophoric flammable or corrosive gas purge the controller thoroughly with a dry inert gas such as nitrogen before disconnecting the gas connections Failure to purge the controller could cause a fire or explosion resulting in death CAUTION the electronic circuitry contains CMOS and NMOS components These are easily damaged by static electricity and usual precautions should be taken when installing dismantling or adjusting the mass flow controller 4 1 0 DISASSEMBLY PROCEDURE 0 Remove any mounting plate that may be under the mass flow 1 Unscrew in and outlet fittings 7 and 8 with a 1 wrench 2 Unscrew 14 and remove the cover 19 3 Remove the sensor screws 15 with a 2 5mm hex screw driver after having the lead wires unsoldered from the p c board Handle the sensor 2 with care a Remove the screw 33 in the bottom of the valve Unsolder the magnet actuator wire from the pc board then remove the 4 screws which hold the magnet to valve body Then carefully lift the magnet Do not turn the mass flow controller now 6 Carefully remove the top housing 24 with the bellows and plunger assembly from the valve housing 23 Then carefully unscrew the lower bellow 7
21. lectronics board amplifies and linearizes the sensor signal so the output of the electronics board named readout gives a signal proportional to the total flow circulating thru the mass flow meter or controller Most of the time this signal is a 0 5 V voltage signal 0 means no flow and 5 V means Full scale of the mass flow The full scale is the maximum flow for which the mass flow is designed and calibrated to work with a good accuracy It is always written on the stickers which are on the top of the cover and the side of the mass flow stainless steel base Also written on the sticker is the gas for which the mass flow is calibrated to work with AFC 202 User s Manual 26 D 10 032 VOO Why using a bypass Because the sensor element can only measure small flow typically 5 sccm So the bypass allow to measure greater amount of flow On a 5 sccm full scale mass flow there is no bypass all the gas flows thru the sensor On a 100 sccm full scale mass flow the bypass is adjusted as when 100 sccm flow thru the mass flow 5 sccm will flow thru the sensor and 95 sccm will flow thru the bypass SENSORS PRINCIPLES Basically the sensor uses the thermal properties of a gas to directly measure the mass flow rate The sensor uses the basic principle that each gas molecule has a specific ability to pick up heat This property called the specific heat Cp directly relates to the mass and physical structure of the molecule and can be determi
22. llers MFCs are used wherever accurate measurement and control of a mass flow of gas is required independently of flow pressure change and temperature change in a given range Mass Flow Meters MFMs are used wherever accurate measurement of gas is required without control of the flow which is done by another device To help understand how an MFC works it can be separated into 4 main components a bypass a sensor an electronic board and a regulating valve FIG 1 Schematic of the mass flow controller The bypass the sensor and one part of the electronic board are the measurement side of the mass flow controller and makes a Mass Flow Meter The regulating valve and the other part of the electronic board are the controlling side of the mass flow controller and exist only on a Mass Flow Controller So every Mass Flow Controller includes a Mass Flow Meter MEASUREMENT PRINCIPLES The flow is divided between a heated sensing tube the sensor where the mass flow is actually measured and a flow restriction or bypass where the majority of flow passes The bypass is designed in a way that flow thru the sensor and thru the bypass is always proportional to the flow range for which the mass flow is build The sensor is designed to deliver an output voltage almost proportional to the gas flow circulating thru it which is due to the bypass design proportional to the total flow circulating thru the mass flow meter or controller The e
23. mely corrosive gases purge with a dry inert gas for one hour AFC 202 User s Manual 10 D 10 032 VOO SECTION 3 ADJUSTEMENT 3 0 REQUIRED FACILITIES To do any adjustment cleaning or replacement on massflow equipment appropriate tools and facilities must be present as these are high accuracy transducers The facilities are 1 An accurate reference massflow measuring system or a flow meter note the pressure and temperature corrections Normal rotameters are not accurate enough The only suffice when relative rough measurements or flow monitoring are necessary 2 A clean room clean tools 3 A voltmeter at least 1000 Q V 4 Supply of gas preferably N2 for safe working 3 1 POTENTIOMETERS ADJUSTMENT To gain access to the p c board carefully remove the cover from the body Every flowmeter and controller is calibrated at the factory for a particular gas and flow range as indicated on the top sticker within 1 If any adjustment is necessary a reference measuring system with at least the same accuracy should be used To remove containment s the unit must be flushed and dried with nitrogen 2 Apply power to the unit and monitor the output signal Obey a warm up time of about 20 minutes 3 With no flow caps on in and outlet fittings adjust the ZERO potentiometer R3 of the unit to obtain a readout on the unit between 5 mV and 15 mV For normally close version set zero to obtain a readout between 20mV and 40 mV to pr
24. ment 3 3 1 NORMALLY CLOSE VALVE Follow 4 2 Potentiometers adjustment then 4 3 Valve adjustment 3 4 DYNAMIC RESPONSE ADJUSTMENT Transient response is adjusted by C6 C3 R24 R11 However AFC 202 is working with high flow and overshoot phenomenon can be critical So it is not recommended to change the factory adjustment Contact you local supplier for special application AFC 202 User s Manual 14 D 10 032 VOO SECTION A MAINTENANCE 4 0 GENERAL No routine maintenance is required on the meters or controllers other than occasional cleaning and re calibration After 3 or 4 years when the unit is run with a ultra clean and non corrosive gas After 1 or 2 years when the unit is run with a low purity gas and or a corrosive gas Cleaning can be performed by removing the unit from the system cleaning inlet and outlet fittings separately and pumping alternately reverse and forward for 5 minutes in each direction with a solvent system one micron maximum absolute filtration Next the unit must be blown with N for 30 minutes minimum Reinstall cleaned fittings In extreme cases of contamination it may be necessary to separately clean the sensor the bypass and the valve 4 1 DISASSEMBLY AND ASSEMBLY PROCEDURES If you disassemble the mass flow controller it will need recalibration in order to reach the specifications given in this manual If the mass flow controller appears to have a fault first perform the c
25. ned experimentally The specific heat is well known for many gases and is generally insensitive to changes in temperature or pressure By adding heat to a gas and monitoring the change in temperature the mass flow rate can be determined To illustrate this concept take the case of cool gas flowing through a heated tube Mathematically the heat loss can be described by the First Law of Thermodynamics q F Cp AT Where q is the heat lost to the gas flow F is the mass flow Cp is the specific heat for a constant pressure AT is the net change in gas temperature as it traverses the tube It is important to realize that both the specific heat and the flow rate determine the amplitude of the heat flux As the mass and physical structure of molecules vary widely from gas to gas so does the specific heat Cp For the same molar flow rate the heat flux can differ significantly for different gases If this heat flux is monitored the amplitude can be converted into an electrical signal Given that the specific heat is known for the gas then the mass flow rate can be determined directly from the electrical signal Now the MFC sensor includes capillary tube wound with two heated resistance and thermometers measuring the change in temperature distribution created by the gas flowing inside this tube heating current Sensor schematic For zero flow the upstream and downstream temperature will be equal The windings are heat
26. ng 31 and screw these over half way the thread length 8 Place the O ring over the upper bellow and put in place in the top Caution The O ring must be very clean clean with alcohol if necessary without any scratch Same think for its chamber in the top housing If not very small leak may occur and with time full the top housing with high pressure with consequence that the valve will stay permanently in open position 9 Place bushing 32 topring 29 and the 4 M3 screws 9 do not yet tighten 10 Preparing lower bellow assy Be assured there is no gap between bellow and and the part screw at the bottom Unscrew and counter sunk the bellow part as necessary 11 Now screw and tighten the lower bellow to the stem coming out the top housing remove first the M3 nut putted during step 4 12 Press on the stem so to center the ball into the seat then tighten the 4 screws 9 Tight the screws togother in order to keep the inner assy in its centered position 13 Adjust the lower bellow lenght at 47 5mm as when it will be mounted into the housing 23 it should not be compressed or extended 14 Assemble top housing 24 to the housing 23 with O ring 37 on bellow assy and O rings 36 and 38 on top housing but without magnet in place for first leak test of the O ring 26 AFC 202 User s Manual 16 D 10 032 VOO 15 Assemble top housing now with O rings 36 and with magnet in place 16 Adjust valve according the normally open valve adjustment pro
27. nit has been packed in two separately sealed plastic bags The outside bag should be removed in the entrance to the clean room The second bag should be removed when you install the unit 2 2 MECHANICAL INSTALLATION 2 2 0 GENERAL Most applications will reguire a positive shutoff valve in line with the mass flow controller Pressurized gas trapped between the two devices can cause surge effects and consideration must be given to the sitting of the shutoff valve upstream or downstream in relation to the process seguencing As far as the process parameters will allow this it is recommended that you install an in line filter upstream to the controller in order to prevent from contamination The AFC 202 can be mounted in any position The atmosphere should be clean and dry The mounting should be free from shock or vibration Mounting dimensions are shown in below Prior to installation ensure that all the piping is thoroughly cleaned and dried Do not remove the protective end caps until you are ready to install the controller AFC 202 User s Manual 7 D 10 032 VOO 20 pin card edge EA AFC 202 En 182 ce Je 4 holes M5 7 Dimensions mm AFC 202 AFM 302 VCR 3 8 MM SWAGELOCK 3 8 VCR 3 8 MM SWAGELOCK 3 8 181 4 183 3 incl Nuts 141 9 143 8 inc
28. o flow Electronics not adjusted Follow Potentiometers Adjustment Valve will not close procedure Contamination Follow General Maintenance or Valve Cleaning Replacement procedure Electronic failure See below Mechanical damage from Adjust valve Valve Adjustment overpressure or other cause procedure or replace valve Change of Calibration procedure Operation on wrong gas often Test on proper gas the case when tested with Ho He or Ar Valve will not open Contamination Follow General Maintenance or Valve Electrically commanded Cleaning Replacement procedure Check closed or potentiometer command signal pins A and B and pot AFC 202 User s Manual 19 D 10 032 VOO shorted Check for electronics failure Clogged inlet fitting screen Clean filter screen appearing as closed valve Valve controls at higher Contamination Follow General Maintenance or Valve flow rates but not at Erosion or corrosion improper Cleaning Replacement procedure minimum adjustment or inadequate Follow Valve Cleaning Replacement drive procedure Adjust valve Valve Adjustment procedure Possible Cause Valve oscillate or hunts Jumpy pressure regulator Replace Improper system dynamics Reduce upstream pressure regulator due to excessive inlet setting pressure Improper dynamics in See Dynamic Response Adjustment electronics General failure or Power supply voltage not Check 15 VDC 15 VDC and 5 00 miscalibration nominal VDC Flow indication satu
29. one year warranty period If MFCs are out of warranty Qualiflow will notify the owner of replacement or repair costs before proceeding Factory service and repairs are guaranteed 90 days The warranty excludes consumable materials and wear parts in teflon viton etc 5 No MFC will be accepted for repair or warranty without a decontamination and purge certificate 6 Each MFC is individually checked visual inspection of fittings helium leak test and flow calibration Qualiflow shall not be responsible for any damage caused by gas leakage or the use of a dangerous gas Users are responsible for following the safety rules applicable to each gas they use Improper use of a Qualiflow MFC will void the warranty and MFCs that have been damaged as a result of improper use will not be replaced by Qualiflow 7 Specific warranty requirements are as follows a Gas must be clean and particle free which means a filter must be fitted in the gas line upstream of the MFC b Gas must comply with the following pressure specifications i Gas pressure must never exceed 10 bars ii Differential pressure must be more than 500 mbar for full scale flow through the MFC valve iii Differential pressure must be less than 3 bars for the MFC valve to regulate without gas flow oscillation iv Pressure at the mass flow inlet must be regulated by an accurate pressure regulator to prevent gas flow oscillation c Electrical connection requirements are as
30. qualif low AFC 202 QUALI FLOW Montpellier headquaters 350 rue A Nobel BP7 34935 MONTPELLIER CEDEX 9 France tel 33 4 67 99 47 47 fax 33 4 67 99 47 48 QUALI FLOW Inc 24 Goose Lane TOLLAND CT 06084 CALIFORNIA USA tel 1 860 871 92 33 fax 1 860 871 92 33 QUALI FLOW Technology Center 909 Boggs Terrace Fremont CA 94539 CALIFORNIA USA tel 1 510 440 93 74 fax 1 510 440 93 75 QUALI FLOW NRT Korea 10 Block 17 Lot Namdong Ind CLX 623 16n Namchon Dong Namdong Ku KOREA tel 82 0 2 3401 6491 fax 82 0 2 3401 6493 AFC 202 User s Manual D 10 032 VOO Identification D 10 032 Revision 100 Date 07 02 01 User s Manual AFC 202 AFC202 Manual doc Control Approved Olivier L onel 07 02 01 Pierre Navratil 07 02 01 Pascal Rudent 07 02 01 History Author Olivier L onel 07 02 01 Initial Version p 00 dued 2000 QUALIFLOW Montpellier France This document contains information proprietary to QUALIFLOW and shall not be used for engineering design procurement or manufacture in whole or in part without consent of QUALIFLOW AFC 202 User s Manual 3 D 10 032 V00 SECTION T INTRODUCTION sr urin ate ae m BREI 5 LD AFC 202 MASS FLOW CONTROLLER 5 LD ARE 202 USERS MANUAL in Be ei sea 5 1 2 SPECIFICA RION EE 5 1 3 CALIBRATION FEATURES susen 6 1 3 0 STANDARD CONDITIONS ne a YF die 6 1 3 1 MANUFACTURING ENVIRONMENT 800 6 132 QUALITY CONTRO iia 6 SECTION 2 INSTALLATION
31. rated Bridge or sensor failure Check sensor resistance 0 7 or 12 VDC Voltage Yellow to common 8 to 10 VDC regardless of flow Pin 6 to common should read 6 2 2 VDC Component Failure Check R3 R9 other components and solder joints Valve drive open or TS2 open or short IC LM 324 Check TS2 LM 324 and other saturated failed components All circuit functional but out Contamination or as a result Adjust see Adjustment procedure of calibration of cleaning or repairing Unit controls but output 5 00 VDC not nominal Check supply Adjust if necessary voltage does not agree with potentiometer setting Large input voltage offset in Check and replace if necessary Op Amp A C6 leaks Replace SECTION 6 WARRANTY AND SERVICES 6 0 PRODUCT WARRANTY 1 Qualiflow products are guaranteed against defects in materials and workmanship for a period of one year from the date of shipment if used in accordance with specifications and not subject to physical damage contamination alteration or retrofit 2 Buyers undertake to check and inspect the goods and to notify Qualiflow of shipment incidents by fax phone or e mail as soon as possible after receipting the goods 3 During the warranty period products must only be repaired by authorized Qualiflow service centers otherwise the Qualiflow product warranty will be invalidated AFC 202 User s Manual 20 D 10 032 VOO 4 Repairs will be performed free of charge during the
32. reooornvovornovornenrerneevennsvenseevenneesernesennseserneneer 24 APPENDIX D GENERAL MFC PRINCIPLES eie O UL FA da gebeten 26 MEASUREMENT PRINCIPLES asien 26 SENSORS PRINGCIBEES vunne add 21 BYPASS PRINCIPLES Sue 29 CONTROL PRINCIPLES Sii is 30 AFC 202 User s Manual 4 D 10 032 VOO SECTION 1 INTRODUCTION 1 0 AFC 202 MASS FLOW CONTROLLER This manual covers the massflow controller AFM 302 and also the massflow meter AFC 202 QUALIFLOW Massflowmeters are rigid accurate transducers which measure the massflow rate of a gas calibrated in standard ranges in sccm or sim They include of a thermal flow sensor a bypass assembly which is a laminar flow device that splits up the flow in order to achieve the required range and a p c board that contains the amplifier and the literaliser These items are built together upon a stainless steel base block All metal parts which are in contact with the gas are made of 316 type Stainless Steel the seals are viton or neoprene depending on the type of gas The output of the flowmeter is a linear signal 0 to 5 VDC directly proportional to the massflow rate Massflow controllers include the same units but extended with a built in automatic control valve An electronic circuit that amplifies the difference between the output signal of the flowmeter and an external selected setpoint value drives the valve in such a way that this difference is reduced to zero Massflow controller AFC 202 can be
33. rom inlet and outlet side at the same time 4 2 SENSOR CLEANING AND REPLACEMENT If it is determined that the sensor is contaminated flush with a solvent in hypodermic needle while running a small wire 0 15 mm diameter available on request Do not immerse the entire sensor assembly in a solvent the solvent will keep under the cover and destroy or at least change the sensor characteristics Slow dry with nitrogen If the sensor resistance has changed or even open circuit is measured the assembly should be replaced The measured resistance between red and green R1 and between red and yellow R2 must be between 160 and 190 Q and QR R2 R1 must be less than 1 Q Check also that there is no short circuit between the tube and the red wire Examine the sensor seals and replace when damaged 4 2 VALVE CLEANING AND REPLACEMENT After having disassembly the valve the status of the shut off ball and the seat in the top housing can be examined The shut off ball can be cleaned with alcohol freon or even a HF solution 5 HF 95 deionised water The conical seat and the ball can be treated with solvent and a felt tip If appropriate polishing equipment is available the seat and shut off ball can be polished After polishing the parts must be cleaned If the critical parts are unfortunately corroded or attacked too much replace Afterwards follow assembling instruction and adjustment instruction AFC 202 User s Manual 18 D 10 032
34. t and cool the 2 winded resistances instead of cooling the first one and heating the second one This is the reason why bypass is necessary for higher full scale than 5 sccm Also the fact that the coefficients N and Cp are different from one gas to another explains why mass flow can NOT be changed from one gas to another without using a special coefficient to converter the measurement or recalibrate the mass flow Because of sensor saturation if flow is ten time the full scale output will be almost no flow This will never happen on a mass flow controller as the valve of the mass flow will act as a restriction and will not allow the gas to flow ten times the full scale But it can easily happened on a mass flow meter as if there is no restriction on the gas line nothing in the mass flow meter will limit the gas flow BYPASS PRINCIPLES Acting as a restrictive element the bypass is composed of a series of capillary tubes or washers held in a special bypass ring The ring fits around the body and may hold up to 24 tubes The number of tubes and their diameter depend on the customer s specifications of gas type and flow range For high flow rates the bypass tubes are replaced by a screen bypass Bypass ring Bypass tubes Bypass tubes O8 Bypass washers equivalent to several thin tubes AFC 202 User s Manual 29 D 10 032 VOO The bypass principles are based on the laminar flow theory When flow is laminar the flow is
35. ut customer s information the MFCs are calibrated under standard conditions 1 3 0 STANDARD CONDITIONS Without special conditions specified by the customer the MFC is calibrated under the following standard conditions Pressure conditions Pressure Outlet Atmospheric Delta Pressure between 500 mbars and 3 bars Dynamic adjustment no overshoot The mounting position horizontal vertical inlet up or down should be specified by the customer to ensure the best accuracy 1 3 1 MANUFACTURING ENVIRONMENT The MFCs are assembled calibrated packaged and controlled in a class 100 cleanroom 1 3 2 QUALITY CONTROL Each MFC is controlled 24 hours after manufacturing on a different calibration bench The accuracy the dynamic response the stability to pressure variations are double checked AFC 202 User s Manual 6 D 10 032 VOO SECTION 2 INSTALLATION 2 0 INTRODUCTION This four part section contains all the information necessary to install the AFC 202 2 1 UNPACKING 2 2 MECHANICAL INSTALLATION 2 3 ELECTRICAL INSTALLATION 2 4 CHECK BEFORE START UP 2 6 COMMUNICATION MODES 2 1 UNPACKING The AFC 202 mass flow controller are manufactured under clean room conditions and has been packed accordingly upon receipt The cardboard packing should be checked for damage If there is visible damage please notify your local QUALIFLOW sales office at once In order to minimize contamination of clean rooms the u
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