Teledyne HFC-303/307 Automobile Parts User Manual
Contents
1. 5 4 HFM 306 7 56 041 FITTIN AGELOK 6 NWAGELOI 1 4 2 84 3WAGELOK 3 6 SWAGELOK 2 2 46 5 ITAL 16 240 29 Manual 152 082010 301 305 306_303 307 Series Page 30 of 35 5 5 307 FITTING TYPE AG 1 NUT 3 54 AG 1 BARE 1 4 16 FACE 2 76 3 FACE 16 58 10 i O 144 78 76 20 1 Y Y 76 20 7 Manual 152 082010 301 305 306 303 307 Series Page 31 of 35 WARRANTY 6 1 Warranty Repair Policy Hastings Instruments warrants this product for a period of one year from the date of shipment to be free from defects in material and workmanship This warranty does not apply to defects or failures resulting from unauthorized modification misuse or mishandling of the product This warranty does not apply to batteries or other expendable parts or to damage caused by leaking batteries or any similar occur2. n elk erri pm T n tts n eum UT erar TEE M eerie f CERE aoa i CoD a E E EUN Figure 3 2 The shunt must generate a pressure drop at the desired full scale flow which drives the proper flow through the sensor tube to generate a full scale output from the sensor Since the full scale flow of the sensor is the same for all of the different full scale flows that may pass through the shunt the geometry must vary for the different full scale flows in order to generate the same pressured drop for all of them This is accomplished by adding more channels to main shunt body As the full scale flow rate increases the flow meter body must get larger to allow room for the increased number of bypass passageways that are required Manual 152 082010 301 305 306 303 307 Series Page 22 of 35 3 7 Control Valve The control valve is an automatic metering solenoid valve see Figure 3 3 While most solenoid valves operate in either the fully open or closed positions the automatic metering solenoid valve is designed to control flow A spring is used to hold a magnetic plunger assembly tightly against an orifice thereby shutting off the flow The magnetic plunger assembly is surrounded by a coil of magnet wire When the Coil is energized the electric current passing through the wire coil produces a magnetic field
3. 0 02696 of reading psi N2 fen tee See pressure section for pressure errors Operating temperature Nt 0 60 in non condensing environment Temperature coefficient zero ps maximum 0 085 0 60 0C Temperature coefficient span 20000000000 0000000004 maximum 0 092 C 15 50 IB issue 1x10 9 std cc s otandard outplt 6 nee taire e re e er a east 0 5 VDC load min 2k Ohms Optional outputs drame c ae aer I i RR 4 20 mA load 600 Ohms Power requirements iie eti ee iui eiie 15 VDC 55 mA meters EP ETC xD 15 VDC 150 mA controller Sond c xd ce T cata UN ede se dise Class 2 power 150VA max Wetted materials ec te 302 304 amp 316 stainless steel nickel 200 Viton act id ees Bader Ee eO EET Kalrez controller only Attitude sensitivity 0 25 F S for 90 without re zeroing eet de here e a uy Es Tas N2 at 19 7 psi 135 Attitude sensitivity lt 0 06 of reading dore Pes PU E DS Dee EY N2 at 19 7 psi 135 KPa WGI A TAL i2 et fist ere de PE RD T PRU sien HFM 301 3 5 lbs 1 6 kg EC EM E HFC 303 5 3 lbs 2 4 kg EE 305 8 0 lbs
4. 1 The most accurate method is by direct measurement Gases that can be handled safely inert gases gases common in the atmosphere etc can be run through a standard flow meter and the GCF determined empirically 2 The National Institute of Standards and Technology NIST maintains tables of thermodynamic properties of certain fluids Using these tables one may look up the necessary thermophysical property and calculate the GCF with the same degree of accuracy as going directly to the referenced investigator 3 amp 4 Many gases that have been investigated sufficiently by other researchers can have their molar specific heat C p calculated The gas conversion factor is then calculated using the following ratio pN2 C GCF pGasX GCF s calculated in this manner have been found to agree with the empirically determined GCF s within a few tenths of a percent Data from investigations that factor in pressure as well as temperature usually supply a higher degree of accuracy in their predictions 5 Forrare expensive gases or gases requiring special handling due to safety concerns one may look up specific heat properties in a variety of texts on the subject Usually data found in this manner applies only in the ideal gas case This method yields GCF s for ideal gases but as the complexity of the gas increases its behavior departs from that of an ideal gas Hence the inaccuracy of the GCF increases Hastings Instruments
5. 3 7 kg eM RI 306 28 8 Ibs 13 2 kg HFC 307 15 3 lbs 6 94 kg Electrical connector eR e a EE 15 pin subminiature Fitting options unon nenna HFM 301 HFC 303 1 2 Swagelok 3 4 Swagelok eo A en 1 2 VCR 1 2 VCO EE 305 307 1 Swagelok amp 1 VCR 1 VCO amp kr fase En tu 306 1 Swagelok 1 VCR 1 2 Swagelok Manual 152 082010 301 305 306 303 307 Series Page 5 of 35 1 3 Optional 4 20 mA Current Output An option to the standard 0 5 output is the 4 20 mA current output that is proportional to flow The 4 20 mA signal is produced from the 0 5 VDC output of the flow meter The current loop output is useful for remote applications where pickup noise could substantially affect the stability of the voltage output The current loop signal replaces the voltage output on pin 6 of the D connector The load must be less than 6000 Failure to meet this condition will cause failure of the loop transmitter 1 4 Other Accessories 1 4 1 Hastings Power supplies Hastings Power Pod power supply display units are available in one and four channel versions They convert 100 115 or 230VAC to the 15 required to operate the flow meter and provide a digital indication of the flow rate Interface terminals for the retransmission of the flow meter analog out
6. Noise can be most pronounced when measuring the flow output with a sampling analog digital A D converter When possible program the system to take multiple samples and average the readings to determine the flow rate If less overall system noise is desired a jumper may be installed over the pins of JP 1 on the flow measurement card See Figure 2 8 Covering the pins closest to the D connector will activate a resistor capacitor RC filter that has a time constant of one second This will change the settling time of _ the indicated flow rate to approximately 4 seconds Covering the other two pins will change the response time to approx 1 second This adjustment will not affect the calibration of the flow meter circuit or the actual flow response to change in command signal flow controllers This will only slow down the indicated response output voltage current 2 10 Controlling Other Process Variables Normally a flow controller is setup to control the mass flow The control loop will open and close the valve as necessary to make the output from the flow measurement match the input on the command line Occasionally gas is being added or removed from a system to control some other process variable This could be the system pressure oxygen concentration vacuum level or any other parameter which is important to the process If this process variable has a sensor that can supply an analog output signal proportional to its value t
7. Span Error vs Pressure for 0 014 Sensors women gt an t Mean Mn 100 200 300 400 500 600 700 800 900 Pressure psig Figure 2 4 Span Error vs Pressure for 0 017 Sensors 1000 Mn 100 200 300 Manual 152 082010 301 305 306 303 307 Series 400 500 600 700 800 900 Pressure psig Figure 2 5 1000 Page 13 of 35 Span Error vs Pressure for 0 026 Sensor 2 0 4 0 0 2 0 4 0 6 0 Q 5 10 0 reading 12 0 14 0 16 0 18 0 20 0 0 100 200 300 400 500 600 700 800 900 1000 Pressure psig Figure 2 6 Manual 152 082010 301 305 306 303 307 Series Page 14 of 35 Span Error 6 reading 0 2 0 4 0 6 0 8
8. 1 0 Span Error vs Pressure 1 0 0 8 pU T ls 0 6 zt 0 4 0 2 ri 0 0 i Mean error min 150 300 Pressure psig Figure 2 7 2 7 4 Blending of Gases In the blending of two gases it is possible to maintain a fixed ratio of one gas to another In this case the output of one flow controller is used as the reference voltage for the set point potentiometer of a second flow controller The set point potentiometer then provides a control signal that is proportional to the output signal of the first flow controller and hence controls the flow rate of the second gas as a percentage of the flow rate of the first gas Manual 152 082010 301 305 306 303 307 Series EXAMPLE Flow controller A has 0 100 slm range with a 5 00 volt output at full scale Flow controller B has 0 10 slm range with a 5 00 volt output at full scale If flow controller A is set at 80 slm its output voltage would be 4 00 volts 80 slm 100 slm x 5 00 volts 4 00 volts If the output signal from flow controller A is connected to the command potentiometer of flow controller B it then becomes a variable reference voltage for flow controller B proportional to the flow rate of flow controll
9. 152 082010 301 305 306 303 307 Series Page 27 of 35 4 5 Printed Circuit Board and Sensor Replacement NOTE This instrument contains static sensitive PC boards Maintain static protection when handling the PC boards In the event that any of the PC boards fail they are easily removed from the instrument and replaced with a spare It is recommended that the metering printed circuit board and sensor be replaced as a unit because they are electronically matched to optimize response time The sensor can also be removed easily This ease in disassembly and replacement substantially reduces instrument downtime 1 Replacement of the 4 20 mA option PC board Unplug the power cable from the instruments D connector Remove the fasteners and steel can The 4 20 mA board is the PC board mounted by a single screw Remove the screw and lift off the 4 20 mA board Be careful not to damage the main board and 4 20 mA board connector 2 Replacement of the main PC board Unplug the power cable from the instruments D connector Remove the fasteners and steel can Remove the 2 screws which fasten the main PC board to the sensor module Gently unplug the main board from the sensor and from the 4 20 mA board if present 3 Replacement of the flow sensor Remove the PC board s as described above Remove the four 4 Allen head cap screws that fasten the sensor to the main instrument base Remove the sensor module from the base discarding the used
10. QUTPUT FILTER ER 16 2 10 CONTROLLING OTHER PROCESS VARIABLES pp 16 2 11 COMMAND INPUT eite ed tete e Ud eoe ted ete cases rhe te e Ae eT ETE ee ede ex 16 2 12 17 2 13 GAIN POTENTIOMETER 2 eec eerie te tete eU e eoe pite ee ete eo ed ede bene 17 2 14 TEMPERATURE COEFFICIENTS A ecteesec ee ceu eee tee cete oc ete phe ee Dee e bee dec dece Tree de cete 18 3 THEORY AND FUNCTION 19 3 1 OVERALL FUNCTIONAL DESCRIPTIONS eere Nei eive EVE E ere 19 3 2 SENSOR RP 19 3 3 SENSOR DHEORY 19 3 4 20 3 5 SHUNT DESCRIPTION NE e e UT E E e RE Ee E E UE eR 21 3 6 SAUNT A O Y M 21 3 7 P E 23 3 8 ELECTRONIC CIRCUTETR ac aere Fe P EE ER E ENTE EU EE E E E e NE E e eH REED EEE 24 3 9 INSTRUMENT PERFORMANGE eek RT E ER ERE B EET PERO EFE PEE ER
11. flow at a range between 25 slm and 2500 slm These instruments are intrinsically linear and have an accuracy of better than 1 F S full scale Hastings mass flow instruments do not require any periodic maintenance under normal operating conditions with clean gases No damage will occur from the use of moderate overpressures 500 psi 3 45MPa or overflows Instruments are normally calibrated with the appropriate standard calibration gas nitrogen then a correction factor is used to adjust the output for the intended gas Calibrations for other gases such as oxygen helium and argon are available upon special order 1 1 Features LINEAR BY DESIGN The HFM 301 305 306 and 303 307 series is intrinsically linear no linearization circuitry is employed Should recalibration a calibration standard is required in the field be desired the customer needs to simply set the zero and span points There will be no appreciable linearity change of the instrument when the flowing gas is changed NO FOLD OVER The output signal is linear for very large over flows is monotonically increasing thereafter The output signal will not come back on scale when flows an order of magnitude over the full scale flow rate are measured This means no false acceptable readings during leak testing MODULAR SENSOR HFM 301 305 306 and HFC 303 307 series incorporates a removable replaceable sensor module Field repairs to units can be achieved
12. in lieu of an output voltage The addition of a 4 20 mA current loop transmitter on a secondary PC board mounted parallel to the main pc board is required to provide this current loop A jumper change is made on the secondary PC board to establish the selected output mode 3 9 Instrument Performance The combination of these principles embodied in the 300 Series give inherently linear and highly accurate output and the typical response time from zero to full flow is also quite good The meter settling time of a 1000 slm full scale flow meter is typically under 0 5 seconds Flow controller response is less than 2 seconds Manual 152 082010 301 305 306_303 307 Series Page 24 of 35 Maintenance 4 1 Authorized Maintenance With proper care in installation and use the flow meter will require little or no maintenance If maintenance does become necessary most of the instrument can be cleaned or repaired in the field Some procedures may require recalibration Do not attempt these procedures unless facilities are available Entry into the sensor or tampering with the printed circuit board will void warranty Do not perform repairs on these assemblies while the unit is still under warranty CAUTION Some parts of the instrument are delicate and other parts are heavy enough to cause an injury if dropped Use extreme care when servicing the instrument The potentiometer positions and the electrical components referred to in the troubleshoo
13. may destroy its electronic components 2 7 2 Zero Check Turn the power supply on if not already energized Allow for a 1 hour warm up Stop all flow through the instrument and wait 2 minutes Caution Do not assume that all metering valves completely shut off the flow Even a slight leakage will cause an indication on the meter and an apparent zero shift For the standard 0 5 output adjust the zero potentiometer located on the lower inlet side of the flow meter until the meter indicates zero For the optional 4 20 mA output adjust the zero potentiometer so that the meter indicates slightly more than 4 mA i e 4 03 to 4 05 mA This slight positive adjustment ensures that the 4 20 mA current loop transmitter is not in the cut off region The error induced by this adjustment is approximately 0 3 of full scale This zero should be checked periodically during normal operation Zero adjustment is required if there is a change in ambient temperature or orientation of the flow meter controller 2 7 3 High Pressure Operation If the instrument is not mounted in a level position when operating at high pressure the increased density of the gas will cause natural convection to flow through the sensor tube This natural convection flow will be proportional to the system pressure and will be seen as a shift in the zero flow output that is directly proportional to the system pressure If the system pressure is higher than 250 psig 1 7 MPa the
14. pressure induced error in the span reading becomes significant The following charts show the mean error and the minimum maximum expected span errors induced by high pressures This error can approach 4 5 at 400 psig for 0 017 sensors For accurate high pressure measurements this error must be corrected Consult your packing list to determine if you have a 0 026 0 017 or 0 014 sensor After determining the sensor tube ID use one of the formulae below to determine the expected mean error expressed as a fraction of the reading Errore 9 887 10 3 4154 1077 8 3288 1075 P 0 026 Sensor 10 Error 1 533 10 yP 3 304 1077 2 1 8313 10 4 P 0 017 Sensor Error 4 1 692 10710 1 776 1077 1 929 10 0 014 Sensor Where P is the pressure in psig and Error is the fraction of the reading in error The flow reading can be corrected as follows Corrected Indication Full Scale Error Where the Indication 15 the indicated flow Full Scale is the full scale reading and Error is the result of the previous formula or read from charts below CAUTION The HFM 306 does not have a high pressure option and is only rated for a maximum working pressure of 300 psig Manual 152 082010 301 305 306 303 307 Series Page 12 of 35 3 2 1 0 1 Error shift reading 2 3 5 4 3 2 1 Error shift 96 reading 0 1 2
15. tensile socket head cap screw Use of a fastener other than the one mentioned here may result in leakage at the seal Recalibration of the 301 303 series instrument is necessary For the HFM 305 307 remove the four 12 point bolts securing the endcap while carefully holding the endcap in place Carefully remove the metal gasket sealed endcap and shunt noting their order and the proper annular orientation of the shunt The shunt position is critical to the flow dynamics and can substantially affect the instrument linearity The shunt can be severely damaged if dropped Examine the shunt If damaged dirty or blocked clean and replace as applicable Reassemble in the reverse order of disassembly replacing the used metal gasket with a new one Secure the endcap with 35 ft lb 47 5 N m to 40 ft lb 54 3 N m of torque on each 12 pt bolt Use of a fastener other than the one mentioned here may result in leakage at the seal Recalibration of the 305 307 series instrument is necessary For the HFM 306 remove the six hex socket bolts from the inlet end cap Remove the end cap and ensure that the o ring is not damaged Remove the flow conditioning screen assembly and if damaged dirty or blocked clean and replace as applicable Carefully remove the flow straightener and shunt assembly If damaged dirty or blocked clean and replace as applicable Reassemble in the reverse order of disassembly Recalibration of the HFM 306 instrument is necessary Manual
16. this sensor tube pass through an aluminum block and into the stainless steel sensor base This aluminum block thermally shorts the ends of the sensor tube and maintains them at ambient temperature There are two coils of resistance wire that are wound around the aluminum block The coils are identical to each other and are symmetrically spaced on the aluminum ambient block These coils are wound from the same spool of wire that is used for the sensor heater coils so they have the same resistivity and the same temperature coefficient of resistance as the sensor heater coils The number of turns is controlled to have a resistance that is 10 times larger than the resistance of the heater coils Thermal grease fills any voids between the ambient temperature block and the sensor tube to ensure that the ends of the sensor tube are thermally tied to the temperature of this aluminum block Aluminum has a very high thermal conductivity which ensures that both ends of the sensor tube and the two coils wound around the ambient block will all be at the same temperature This block is in good thermal communication with the stainless steel base to ensure that the ambient block is at the same temperature as the main instrument block and therefore the same temperature as the incoming gas stream This allows the coils wound on the aluminum block to sense the ambient gas temperature Two identical Wheatstone bridges are employed as shown in Figure 3 2 Each bridge util
17. voc AUTO Table 2 1 Pin out us Do not use Do not use Do not use Do not use Signal Common Output 0 5 VDC 4 20mA Case Ground Valve Override 15 VDC Do not use 15 VDC Signal Common 1 2 3 4 5 6 7 8 9 10 11 12 13 External Input Set Point 0 5 VDC 4 20mA Do not use Manual 152 082010 301 305 306 303 307 Series Page 9 of 35 Figure 2 2 0 5 15 COMMON FLOW CONTROLLER FLOW CONTROLLER OUTPUT VALVE CONTROL MODE 0 CONNECTIONS 15 vc O 15 voc AUTO Table 2 2 U Pin out Signal Common Do not use Do not use 15 VDC Output 0 5 VDC 4 20mA Signal Common Case Ground Valve Override Pin 1 2 3 4 5 6 7 8 9 10 11 15 VDC External Input o N Signal Common _ AR Signal Common Set Point 0 5 VDC 4 20mA Manual 152 082010 301 305 306 303 307 Series Page 10 of 35 2 6 4 20 mA Connections The 300 Series flow meters have a 4 20 mA current output option available as an alternative to the standard 0 5 VDC output This current output is useful for remote applications where noise pick up could substantially affect the stability of the voltage output The 4 20 mA signal is produced from the 0 5 output of the flow meter and replaces the voltage output on pin 6 of the connector The current is sourced by the flow controller and the metering cir
18. with a minimum of production line downtime Calibration is required FAST SETTLING TIME Changes in flow rate are detected in less than 500 milli seconds when using the standard factory PC board settings Controller response is typically 2 seconds LOW TEMPERATURE DRIFT The temperature coefficient of span for the HFM 301 HFC 303 series 15 less than 0 092 of full from 0 60 C The temperature coefficient of zero is less than 0 085 of reading C from 0 60 C FIELD RANGEABLE The HFM 305 and HFC 307 are available in ranges from 1000 slm to 2500 slm The HFM 301 and HFC 303 are available from 25 1000 slm Each flow meter has a shunt and transducer which can be exchanged in the field to select different ranges Calibration however is required e CURRENT LOOP The 4 20 mA option gives the user the advantages of a current loop output to minimize environmental noise pickup Manual 152 082010 301 305 306 303 307 Series Page 4 of 35 1 2 Specifications RE Hs 301 305 amp 303 307 1 full scale F S UP 306 3 full scale F S Repeatability 0 07 of F S Maximum us eee i b ERE EN E ree e eue 500 psi 3 45 MPa e 300 psi HFM 306 Maximum pressure o tie 1000 psi 6 9 MPa MM with high pressure option on HFM 301 HFC303 only Pressure o pter
19. E EXER E een ee 24 4 MAINTENANCE N 25 4 1 AXUTHORIZED MAINTENANCE denies 25 4 2 TROUBLESHOOTING ss eoe nee ete e e ave aec esr cert eed eve ce ee eee Ee SiR 25 4 3 652 e abc tM cc 26 4 4 END CAP REMOVAL eret here ver etae heroe e e else ue idee c Ne Te A E EA 27 4 5 PRINTED CIRCUIT BOARD AND SENSOR REPLACEMENT ppp 28 5 E 29 5 1 MH 29 5 2 30 Seni Heec te ee v 29 5 3 SU 30 54 FEE BE CHEER 30 5 5 EIE 31 6 WARRANTY E 32 6 1 WARRANTY REPAIR POLICY 32 6 2 NON WARRANTY REPAIR POLICY enum uideat ad edad 32 7 EYdudodbq 33 7 1 APPENDIX l VOLUMETRIC VERSUS MASS FLOW pp 33 3 2 APPENDIX 2 GAS CONVERSION FACTORS pp 34 Manual 152 082010 301 305 306 303 307 Series Page 3 of 35 General Information The Hastings 300 Series high range mass flow meters are designed to accurately measure mass flow at a range between 25 slm and 10000 slm The Hastings 300 Series high range mass flow controllers are designed to accurately measure and control mass
20. RTMENT TELEPHONE 757 723 6531 TOLL FREE 1 800 950 2468 FAX 757 723 3925 E MAIL hastings_instruments teledyne com INTERNET ADDRESS http www teledyne hi com Repair Forms may be obtained from the Information Request section of the Hastings Instruments web site Manual 152 082010 301 305 306 303 307 Series Page 32 of 35 7 Appendix 7 1 Appendix 1 Volumetric versus Mass Flow Mass flow measures just what it says the mass or number of molecules of the gas flowing through the instrument Mass flow or weight per unit time units are given in pounds per hour lb hour kilograms per sec kg sec etc When your specifications state units of flow to be in mass units there is no reason to reference a temperature or pressure Mass does not change based on temperature or pressure However if you need to see your results of gas flow in volumetric units like liters per minute cubic feet per hour etc you must consider the fact that volume DOES change with temperature and pressure To do this the density grams liter of the gas must be known and this value changes with temperature and pressure When you heat a gas the molecules have more energy and they move around faster so when they bounce off each other they become more spread out therefore the volume is different for the same number of molecules Think about this The density of Air at 0 is 1 29 g liter The density of Air at 25 C is 1 19 g liter The differen
21. TELEDYNE HASTINGS INSTRUMENTS INSTRUCTION MANUAL HFM 301 305 306 FLOW METERS HFC 303 307 FLOW ASA TELEDYNE HASTINGS INSTRUMENTS C 4 ISO 9001 A Teledyne Technologies Company CERTIFIED Manual Print History The print history shown below lists the printing dates of all revisions and addenda created for this manual The revision level letter increases alphabetically as the manual undergoes subsequent updates Addenda which are released between revisions contain important change information that the user should incorporate immediately into the manual Addenda are numbered sequentially When a new revision is created all addenda associated with the previous revision of the manual are incorporated into the new revision of the manual Each new revision includes a revised copy of this print history page Revision F Document Number 152 082002 pp August 2002 Revision G Document Number 152 102002 pp October 2002 Revision H Document Number 152 082005 pp August 2005 Revision J Document Number 152 042006 pp March 2006 Revision Document Number 152 062008 pp June 2008 Revision L Document Number 152 082008 pp August 2008 Revision M Document Number 152 082009 pp August 2009 Revision Document Number 152 102009 October 2009 Revision P Document Number 152 082010 pp August 2010 Exp Visit www teledyne hi com for WEEE disposal guidance The instruments described in this manual are avail
22. a N The HFM 305 and HFC 307 are provided with 1 Swagelok VCR or VCO fittings The HFM 306 can have 1 or 2 Swagelok fittings It is suggested that all connections be checked for leaks after installation This can be done by pressurizing the instrument do not exceed pressure rating of the instrument and applying a diluted soap solution to the flow connections 2 5 Electrical Connections DANGER Care must be taken to avoid high voltages that may be present when dealing with power supplies If a power supply from Hastings Instruments is used installation consists of connecting the 300 Series cable from the connector on the rear of the power supply to the connector on the top of the flow meter controller The pin out requires cable AF 8 AM grey molded back shell The pin out requires cable 65 791 black molded back shell If a different power supply is used follow the instructions below when connecting the flow meter and refer to either table 2 1 or 2 2 for the applicable pin out The power supply used must be bipolar and capable of providing 15 at 55 mA for flow meter applications and 15 at 150 mA for controllers These voltages must be referenced to a common ground One of the pins of the Hastings instrument must be connected to the common terminal of the power supply Case ground of the instrument should be connected to the AC ground locally The cable shield if ava
23. able with multiple pin outs CAUTION Ensure that all electrical connections are correct CAUTION The instruments described in this manual are designed for INDOOR use only The instruments described in this manual are designed for Class 2 installations CAUTION in accordance with IAW IPC standards Hastings Instruments reserves the right to change or modify the design of its equipment without any obligation to provide notification of change or intent to change Manual 152 082010 301 305 306 303 307 Series Page 2 of 35 Table of Contents 1 GENERAL INFORMATION RE N 4 1 1 BEATURBST A np Men Eure Uu terr ets 4 1 0 Nigel e WONDERED 5 1 3 OPTIONAL 4 20 CURRENT OUTPUT ppp 6 1 4 OTHER ACCESSORIES e ene 6 2 OPERATION ois er 7 2 1 RECEIVING INSPECTION EC E PARED ERE EP E EE E EO RECEN Le a EON ETT 7 2 2 POWER REQUIREMENTS eret E CER P OP EE RE ERI ERES E ESAE DE ETE ERA CUN 7 2 3 OUTPUT SIGNAL 7 ere ERE EE E EE RE EFE EE PER 7 2 4 MECHANICAT CONNECTIONS 7 2 5 BLECTRICAT CONNECTIONS 8 2 6 4 20MA GONNEGTIONS 5 eere ete creciente tete mentre 11 2 OPERATION RR 12 2 8 RANGE CHANGING edente 16 2 9
24. acy Note the flow signal decays toward zero Run 20 flow 1 VDC through instrument for 5 minutes Insure zero flow wait 2 minutes then zero the instrument 7 Instrument is ready for operation 2 2 Power Requirements The HFM 301 305 306 requires 15 VDC 55 mA The HFC 303 307 requires 15VDC 150 mA for proper operation The supply voltage should be sufficiently regulated to no more than 50 mV ripple The supply voltage can vary from 14 0 to 16 0 VDC Surge suppressors are recommended to prevent power spikes reaching the instrument The Hastings power supply described in Section Error Reference source not found satisfies these power requirements 2 3 Output Signal The standard output of the flow meter is a 0 5 signal proportional to the flow rate In the Hastings power supply the output is routed to the display and is also available at the terminals on the rear panel If a Hastings supply is not used the output is available on pin 6 of the connector It is recommended that the load resistance be no less that 2 If the optional 4 20 mA output is used the load impedance must be less than 600 2 4 Mechanical Connections The flow meter may be mounted in any position as long as the direction of gas flow through the instrument follows the arrow marked on the bottom of the flow meter case label The preferred orientation is with the inlet and outlet fittings in a horizontal plane If operating
25. al to the heater temperature it can be shown that the differential power is 2MC Trae Pod The value of the constant pressure specific heat of a gas is virtually constant over small changes in temperature By maintaining both heaters at the same constant temperature difference above the ambient gas stream temperature the difference in heater power is a function only of the mass flow rate Fluctuations in ambient gas temperature which cause errors in conventional mass flow sensors are avoided The resistance of the ambient sensing coil changes proportionally with the ambient temperature fluctuations causing the closed loop control to vary the bridge voltage such that the heater resistance changes proportionally to the ambient temperature fluctuation The power supplied to each of the 2 heater coils is easily obtained by measuring the voltage across the heater shown as V2 on Figure 3 2 and the voltage across the fixed resistor R1 Since R1 is in series with the heater RH they have the same current flowing through them The electrical power supplied to a given heater is then calculated 2 V ux V R With a constant differential temperature applied to each heater coil and no mass flow through the sensor the difference in heater power will be zero As the mass flow rate through the sensor tube is increased heat is transferred from the upstream heater to the gas stream This heat loss from the heater to the gas stream wi
26. as a standard sealing material The HFM 305 306 is made from a larger 3 0 by 3 0 76 2 mm by 76 2 mm cross section of 316 stainless steel and has a length of 5 3 134 6 mm while the 307 has a length of 8 203 2 mm The 305 307 however has a larger 2 67 67 8 mm internal flow channel and knife edge metal to metal seals on the end caps Between the base and sensor module on the 300 Series is a knife edge metal to metal seal Gaskets made of nickel 200 are swaged between mating face seals machined into the stainless steel parts All seals are tested at the factory and have leak rates of less than 1x10 std cc s The HFM 306 base is much larger The base end cap seal is an O ring gland configuration which uses Viton as a standard sealing material 3 5 Shunt description The flow rate of interest determines the size of the shunt required As previously indicated the 301 305 series can be configured from 25 to 2500 slm 303 307 controller from 25 2500 slm using various base shunt and transducer combinations The shunts employ a patented method of flow division which results in a more linear flow meter controller further calibration is more stable when changing between measured gases The shunts are comprised of a 316 stainless steel cylindrical shell concentrically located in the base that forms an annular flow channel of precise dimension This flow channel creates laminar flow by the inboard sensor taps The cylindrical shell encases a cor
27. ce is 0 1 g liter If you are measuring flows of 100 liters per minute and you don t use the correct density factor then you will have an error of 10 g minute Volume also changes with pressure Think about a helium balloon with a volume of 1 liter If you could scuba dive with this balloon and the pressure on it increases What do you think happens to the weight of the helium It stays the same What would happen to the volume 1 liter It would shrink Why is the word standard included with the volume terms liters and cubic feet in mass flow applications A mass flow meter measures mass and we know we can convert to volume To use density we must pick one or standard temperature and pressure to use in our calculation When this calculation is done the units are called standard liters per minute SLM or standard cubic feet per minute SCFM for instance because they are referenced to a standard temperature and pressure when the volume is calculated Using the example to the left we can see a standard liter can be defined differently The first balloon contains 0 179 grams of Helium at 0 and 760 Torr density of 0 179 grams liter Heat up that balloon to room temperature and the volume increases but the mass has not changed The volume is not 1 liter anymore it is 1 08 liters So to define a standard liter of Helium at 25 we must extract only one liter from the second balloon and that liter weighs only 0 175 gra
28. continually searches for better estimates of the GCF s of the more complex gases and regularly updates the list Most Hastings flow meters and controllers are calibrated using nitrogen The conversion factors published by Hastings are meant to be applied to these meters To apply the GCF s simply multiply the gas flow reading and the GCF for the process gas in use For example to calculate the actual flow of argon passing through a nitrogen calibrated meter that reads 20 sccm multiply the reading and the GCF for argon 20 x 1 4047 28 094 Conversely to determine what reading to set a nitrogen calibrated meter in order to get a desired flow rate of a process gas other than nitrogen you divide the desired rate by the GCF For example to get a desired flow of 20 sccm of argon flowing through the meter divide 20 sccm by 1 4047 Manual 152 082010 301 305 306 303 307 Series Page 34 of 35 20 1 4047 14 238 That is you set the meter to read 14 238 sccm Some meters specifically the high flow meters are calibrated in air The flow readings must be corrected for the case where a gas other than air is flowing through the meter In addition there must be a correction for the difference in the GCF from nitrogen to air In this case multiply the reading and the ratio of the process gas GCF to the GCF of the calibration gas For example a meter calibrated in air is being used to measure the flow of propane The reading from the meter is mul
29. cuit must sink the current such that the current loop is completed through power supply common connections The load must be less than 600 Ohms Failure to meet this condition will cause failure of the loop transmitter The 300 Series flow controllers have a 4 20 mA current input option available as an alternative to the standard 0 5 VDC command input The controller sinks the input current through a 77 Ohm load to power supply common POWER SUPPLY HASTINGS FLOW CONTROLLER PIN OUT PLC ANALOG 1 0 CARD PIN 7 POWER IN ANALOG OUT SETPOINT INPUT PIN 14 sd ANALOG RETURN 9 SNHO 009 0 Figure 2 3 Manual 152 082010 301 305 306 303 307 Series Page 11 of 35 2 7 Operation The standard instrument output is a 0 5 and the signal is proportional to the flow i e 0 volts zero flow and 5 volts 100 of rated flow The 4 20 mA option is also proportional to flow 4 mA zero flow and 20 mA 100 of rated flow 2 7 1 Operating Conditions For proper operation the combination of ambient temperature and gas temperature must be such that the flow meter temperature remains between 0 and 60 C Most accurate measurement of flow will be obtained if the flow meter is zeroed at operating temperature as temperature shifts result in some zero offset The 300 Series is intended for use in non condensing environments only Condensate or any other liquids which enter the flow meter
30. e 300 series instruments require a different cable to connect to the power supply This cable is identifiable by black back shells and is available as Hastings Instrument 465 791 Manual 152 082010 301 305 306 303 307 Series Page 6 of 35 Operation This section contains the necessary steps to assist in getting a new flow meter controller into operation as quickly and easily as possible Please read the following thoroughly before attempting to install the instrument 2 1 Receiving Inspection Carefully unpack the Hastings 300 Series instrument and any accessories that have also been ordered Inspect for any obvious signs of damage to the shipment Immediately advise the carrier who delivered the shipment if any damage is suspected Check each component shipped with the packing list Insure that all parts are present i e flow meter power supply cables etc Optional equipment or accessories will be listed separately on the packing list There may also be one or more OPT options on the packing list These normally refer to special ranges or special gas calibrations They may also refer to special helium leak tests or high pressure tests In most cases these are not separate parts but special options or modifications built into the flow meter Quick Start Insure flow circuit mechanical connections are leak free Insure electrical connections are correct See label Power up Allow 30 minutes to 1 hour warm up for best accur
31. er A If the set point potentiometer of flow controller B is set at 50 of full scale and the reference voltage from flow controller A is 4 00 then the command signal going to flow controller B would be 2 00 volts 4 00 volts x 50 0 2 00 volts The flow of gas through flow controller B is then controlled at 4 slm 2 00 volts 5 00 volts x 10 slm 4 slm The ratio of the two gases is 20 1 80 slm 4slm The mixture of gas A is 95 2 80slm 84slm and the mixture of gas B is 4 8 4 slm 84 slm Should the flow of flow controller A drop to 78 slm flow controller B would drop to 3 9 slm hence maintaining the same ratio of the mixture 78 slm 100slm x 5v 3 90v x 50 1 95v 1 95v 5 00v X 10 slm 3 9 slm 78 slm 3 9 slm 20 1 Page 15 of 35 2 8 Range Changing Changing the range of flow controller can be done in the field but calibration is required It is recommended however that the unit be sent back to the factory along with the new range desired gas and operating parameters Consult factory for more information 2 9 Output Filter The flow output signal may have noise superimposed on the mean voltage levels This noise may be due to high turbulence in the flow stream that the fast sensor is measuring or it could be electrical noise when the flow meter has a high internal gain i e 5 sccm full scale meter Varying levels of radio frequency noise or varying airflow over the electronics cover can also induce noise
32. gure 4 1 Incorrect resistance values indicate that the sensor unit needs to be replaced 5678 4321 Figure 4 1 Manual 152 082010 301 305 306 303 307 Series Page 25 of 35 Symptom Sensor has proper resistance readings but little or no output with flow Cause Plugged sensor Action Shut off gas supply and disconnect the power to the flow meter Remove cover and PC board from unit Remove and inspect sensor If sensor has evidence of clogging clean or replace as applicable Symptom Flow meter reads other than 0 00 VDC with no flow or there is a small flow when the flow meter reads 0 00 VDC Cause Zero pot is out of adjustment Action Shut off all flow For the standard 0 5 VDC output adjust the zero potentiometer see Section 4 3 located on the upper right inlet side of the flow meter until the meter indicates zero For the optional 4 20 mA output adjust the zero potentiometer so that the meter indicates slightly more than 4 mA i e 4 03 to 4 05 mA This slight positive adjustment ensures that the 4 20 mA transmitter is not in its cut off region The error induced by this adjustment is approximately 0 3 of full scale Symptom Flow meter is out of calibration and non linear Cause Leaks in the gas inlet or outlet fittings Action Check all fittings for leaks by placing soap solution on all fittings between gas supply and final destination of gas Check flow meter for leaks Replace if re
33. hen the flow controller may be able to control this variable directly This analog output signal could be 0 5 Volts 0 10 Volts or 4 20 mA for units with 4 20 mA boards any value in between On the CONTROLLER card there is a jumper JP 1 that sets whether the control loop controls mass flow or an external process variable See Figure 2 9 If the jumper connects the top two pins the loop controls mass flow If the jumper connects the bottom two pins the loop controls an external process variable This process variable signal must be supplied on pin 13 of the D connector for H pin out units or pin 12 of the D connector for U pin out units of the measurement card When the controller is set for external variable control it will open or close the valve as necessary to make the external process variable signal match the command signal The command signal may be 0 5 Volts 0 10 Volts 4 20 mA for 4 20 mA input output cards or any value in between If the process variable has a response time that is much faster or slower than the flow meter signal it may be necessary to adjust the gain potentiometer 2 11 Command Input The flow controller will operate normally with any command input signal between 0 10 Volts 4 20 mA for units with 4 20 mA input output cards If the command signal exceeds x14 volts it may damage the circuit cards During normal operation the control loop will open or close the valve to bring the output Ma
34. ilable should be connected to AC ground at the either the power supply end or the instrument end of the cable not at both Pin 6 is the output signal from the flow meter The standard output will be 0 to 5 where 5 VDC is 100 of the rated or full scale flow The command set point input should be a 0 5 VDC signal or 4 20mA if configured as such and must be free of spikes or other electrical noise as these would generate false flow commands that the controller would attempt to follow The command signal should be referenced to signal common A valve override command is available to the flow controller Connect the center pin of a single pole three position switch center off to the override pin Connect 15 to one end of the three position switch and 15 VDC to the other end The valve will be forced full open when 15 VDC is supplied to the override pin and full closed when 15 VDC is applied When there is no connection to the pin the three position switch is centered the valve will be in auto control and will obey the 0 5 VDC commands supplied to command set point input Figure 2 1 and Table 2 1 show the 300 Series H pin out Figure 2 2 and Table 2 2 show the 300 Series U pin out Manual 152 082010 301 305 306_303 307 Series Page 8 of 35 Figure 2 1 COMMAND VOLTAGE 0 5 15 COMMON FLOW CONTROLLER OUTPUT VALVE CONTROL MODE H PIN OUT CONNECTIONS 15 vc O 15
35. izes an ambient temperature sensing coil and a heater coil The heater coil and a constant value series resistor comprise the first leg of the bridges The second leg of each bridge contains the ambient sensing coil and two constant value series resistors These Wheatstone bridges keep each heater temperature at a fixed value of AT 48 above the ambient sensor temperature through the application of closed loop control and the proper selection of the constant value bridge resistors 3 3 Sensor Theory The heat transferred by convection to or from a fluid is proportional to the mass flow of that fluid Since the constant differential temperature sensor has 2 heater coils symmetrically spaced on the sensor tube it is convenient to consider the upstream and downstream heat transfer modes separately The electrical power supplied to either of the heater coils will be converted to heat which can be dissipated by radiation conduction or convection The radiation term is negligible due to the low temperatures used by the sensor and because the sensor construction preferentially favors the conductive and convective heat transfer modes The thermal energy of each heater will then be dissipated by conduction down the stainless steel sensor tube conduction to the insulating foam plus the convection due to the mass flow of the sensed gas Because great care is taken to wind the resistive heater coils symmetrically about the midpoint of the tube it is a
36. ll force the upstream bridge control loop to apply more power to the upstream heater so that the 48 C constant differential temperature is maintained The gas stream will increase in temperature due to the heat it gains from the upstream heater This elevated gas stream temperature causes the heat transfer at the downstream heater to gain heat from the gas stream The heat gained from the gas stream forces the downstream bridge control loop to apply less power to the downstream heater coil in order to maintain a constant differential temperature of 48 The power difference at the RTD s is a function of the mass flow rate and the specific heat of the gas Since the heat capacity of many gases is relatively constant over wide ranges of temperature and pressure the flow meter may be calibrated directly in mass units for those gases Changes in gas composition require application of a multiplication factor to the nitrogen calibration to account for the difference in heat capacity 3 4 Base The 316 stainless steel base has a 2 0 by 2 0 50 8 mm by 50 8 mm cross section and is 5 77 146 6 mm long on the HFC 303 and 4 32 109 7 mm long on the HFM 301 Lower flow 300 SLM 301 s are 0 2 shorter and lower flow 303 s are 0 4 shorter The base has an internal flow channel that is Manual 152 082010 301 305 306 303 307 Series Page 20 of 35 1 75 44 5 mm diameter The base and endcap seal is an O ring gland configuration which uses Viton
37. mand to 100 of full scale 4 Perform this step only if a calibrated reference flow meter is available Adjust Span pot see Figure 4 2 until the indicated flow reads full scale 5 00 VDC or 20 mA and the reference meter controller reads the desired full scale flow rate 5 Record flow meter controller and flow reference outputs for flow rates of 20 40 60 80 and 100 and make sure data are within 1 of full scale Manual 152 082010 301 305 306 303 307 Series Page 26 of 35 Control Loop Gain Zero Span Figure 4 2 4 4 End Cap Removal The end cap on the inlet side must be removed to gain access to shunt assembly First remove power and shut off the supply of gas to the instrument Disconnect the fittings on the inlet and outlet sides of the transducer and remove it from the system plumbing On both the HFM 301 and HFC 303 remove the four Allen head screws holding the end cap to the instrument Carefully remove the O ring sealed end cap and shunt noting their order and the proper annular orientation of the shunt The shunt position is critical to the flow dynamics and can substantially affect the instrument linearity The shunt can be severely damaged if dropped Examine the shunt If damaged dirty or blocked clean and replace as applicable Reassemble in the reverse order of disassembly Secure the endcap with 65 in lb 7 3 N m to 85 in lb 9 6 N m of torque on each high
38. ms If a mass flow meter is set up for STP at 0 C and Liter 1 08 Liter Liter 760 Torr when it measures 0 179 grams of He it 0 25 25 will give you results of 1 SLM If a second meter 0 179 grams 1 0 179 g 1 08 0 164 grams is set up for STP at 25 C and 760 Torr when it liter liters measures 0 164 grams it will give results of 1 Manual SLM 152 082010 301 305 306 303 307 Series Page 33 of 35 7 2 Appendix 2 Gas Conversion Factors Gas conversion factors GCF s for gasses metered using Hastings Instruments products can be found by visiting the Hastings Instruments web site The web address can be found at the end of this document The gas conversion factors GCF s provided by Hastings Instruments HI fall into five basic accuracy domains that to a large extent are dependent on the method by which they are found The following table summarizes the different methods used to determine the GCF s The table lists the methods in decreasing order of the degree of accuracy that may be achieved when applying a conversion factor Methods Used to Determine Gas Conversion Factors Determined empirically at Hastings Instruments Calculated From NIST tables Calculated using the virial coefficients of independent investigators empirical data using both temperature and pressure as variables 4 Calculated from virial coefficients using temperature only 5 Calculated from specific heat data at 0 C and 1 atmosphere Wn
39. nd it will also vary when the gas composition changes This will cause the magnitude of the pressure drop due to the area change to be a function of system pressure and gt gas composition Most of the shunts used contain or can be gt approximated by many short capillary tubes in b parallel We know that the equation for the pressure drop across a capillary tube contains Ludum terms that are proportional to the square of the 1 volumetric flow rate These terms come from the pressure drops associated with the sudden POETE eee best 3 TTE e E Figure 3 ompression at the entrance and the sudden expansion at the exit of the capillary tube end effect terms are a function of density which will cause the quadratic term to vary with system pressure and gas composition The absence of viscosity in the second term will cause a change in the relative magnitudes of the two terms whenever the viscosity of the flowing gas changes Manual 152 082010 301 305 306 303 307 Series Page 21 of 35 128uLQ 820 The end effects for a typical laminar flow element air account for approximately 4 of total pressure drop For hydrogen however which has a density that is about 14 times less than air and has a viscosity that is much greater than air the second term is completely negligible For the heavier gasses such as sulfur hexafluoride which has a den
40. nickel gaskets New nickel gaskets are required for re assembly To place an order or to obtain information concerning replacement parts contact the factory representative in your area See section 6 in this manual for the address or phone number When ordering include the following information Instrument model number part description and Hastings part number Manual 152 082010 301 305 306 303 307 Series Page 28 of 35 Outline Drawings 5 1 HFM 301 PIN D CONNECTION Eu 501 1 2 FITTING 4 HFM 301 3 4 FITTING FITTING TYPE DIM A 3 4 16 FEMALE 411 39 1 FITTING TYPE 6 31 160 27 12 FEVALE 1 A Y di z sie MOUNTING 5 2 HFC 303 LE HFC 303 1 2 FITTING HFC 303 5 4 FITTING FITTING 1 12 FEMALE 5 8 32 X 48 DP gt Manual 152 082010 301 305 306 303 307 Series Page 29 of 35 5 3 305
41. ns the sample flow would be affecting the flow it was trying to measure If the sensor tube is made large enough and with enough flow through it to insert the sensor taps at these positions then the pressure drop would be too small to push the necessary flow through the sensor tube The solution is to use a different geometry for the flow tube It must be large enough to allow the sample points in the middle yet with passages thin enough to create the differential pressures required for the sensor An annular passage meets these requirements of the 400 series shunts have annular passageway that passes between the outside of the main shunt body and the inside edge of the base where the sensor taps are located UTD E E TTE T TE ee x rp uec 202261224 odia aeri e aaa iru E ped SEITEN PITE PETER EE EE QE nee mee crees MURIS d emet niea aere mme mad nan AEE T E E TTE RD E Sta UAE CC ORE E aS xe m ETAT eme TERUEL Mea ENTE Fuge ED Db ETE e C EM E E i aoc EE m erc e M UE a erai IPC ere ir bp n IRE i Ex a nan i a ela ETE QU UE repu eis crudi qu JM cepe rae Dry d eS Nri M tena um dA ET ars
42. nual 152 082010 301 305 306 303 307 Series Page 16 of 35 of the flow meter signal to within 0 001 Volts of the command signal The command signal will not match the flow signal if there is insufficient gas pressure to generate the desired flow If the command signal exceeds 5 Volts the controller will continue to increase the flow until the output matches the command signal However the flow output may not maintain the published accuracy values under these conditions If the command signal is less than 126 of full scale 0 05 Volts or 4 16 mA the valve override control circuit will activate in the closed position This will force the valve completely closed regardless of the flow signal 2 12 Valve Override Control The valve override control line provides a method to override the loop controller and open or close the valve regardless of the flow or command signals During normal operation this line must be allowed to float freely This will allow the loop control to open and close the valve as it requires If the valve override line is forced high gt 5 Volts the valve will be forced full open If the valve overrides line is forced negative 5 Volts the valve will be forced closed Control Loop 2 13 Gain Jumper Potentiometer On the top left of the inlet side of the flow controller there is a hole through which the gain potentiometer is accessible See Figure 2 9 and Figure 4 2 This gain potentiometer affect
43. put signal are located on the rear of the panel The Power Pod 100 and 400 models are built with controllers in mind but will work with meters as well The Model 40 is for flow meters only Throughout this manual when reference is made to a power supply it is assumed the customer is using a Hastings power supply Hastings PowerPod 100 and PowerPod 400 power supplies are CE marked but the Model 40 does not meet CE standards at this time The Model 40 and PowerPod 100 are not compatible with 4 20 mA analog signals With the PowerPod 400 individual channels input signals as well as their commands become 4 20 mA compatible when selected The PowerPod 400 also sports a Totalizer feature More information about the Power Pods can be found on the Hastings web site http www teledyne hi com products powerpod series htm 1 4 2 Interconnecting Cables Cables are available from Hastings in various lengths to connect from the 15 pin D connector on the back of the Power Pod directly to any of the 200 series and 300 series flow instruments including digital versions More information about the available cables can be found in the Power Pod 400 bulletin on the Hastings web site http www teledyne hi com pdfs bulletins htm The 300 series flow instruments normally come with the standard H pin out connector This type of connector is supplied on the Hastings AF 8 AM series cables with grey backshells such as 765 149 U pin out versions of th
44. quired or recalibrate as necessary Symptom Little or no flow even when the valve is in override OPEN Cause Blocked orifice or incorrect pressure across the flow controller Action Verify that there is 10 to 15 psig pressure across the instrument If the differential pressure across the instrument is correct the orifice may be obstructed Remove all gas pressure and shut off power supply Remove the valve 4 3 Adjustments 1 Connect power to D connector as specified in Section 2 5 Allow the instrument to warm up for at least 30 minutes 60 minutes for best accuracy Note the flow signal decays toward zero Run 20 of flow range 1 VDC through instrument for 5 minutes 2 Completely shut off the flow and wait for 2 minutes For the standard 0 5 VDC output adjust the zero potentiometer located on the lower inlet side of the flow meter see Figure 4 2 until the meter indicates zero For the optional 4 20 mA output adjust the zero potentiometer so that the meter indicates slightly more than 4 mA i e 4 03 to 4 05 mA This slight positive adjustment ensures that the 4 20 mA transmitter is not in its cut off region The error induced by this adjustment is approximately 0 3 of full scale 3 Turn on gas supply to inlet of instrument and adjust the flow rate to the desired full scale flow as indicated by a reference flow meter controller If the instrument to be calibrated is a controller adjust the flow rate by setting the com
45. rence This warranty does not apply to any instrument which has had a tamper seal removed or broken This warranty is in lieu of all other warranties expressed or implied including any implied warranty as to fitness for a particular use Hastings Instruments shall not be liable for any indirect or consequential damages Hastings Instruments will at its option repair replace or refund the selling price of the product if Hastings Instruments determines in good faith that it is defective in materials or workmanship during the warranty period Defective instruments should be returned to Hastings Instruments shipment prepaid together with a written statement of the problem and a Return Material Authorization RMA number Please consult the factory for your RMA number before returning any product for repair Collect freight will not be accepted 6 2 Non Warranty Repair Policy Any product returned for a non warranty repair must be accompanied by a purchase order RMA form and a written description of the problem with the instrument If the repair cost is higher you will be contacted for authorization before we proceed with any repairs If you then choose not to have the product repaired a minimum will be charged to cover the processing and inspection Please consult the factory for your RMA number before returning any product repair TELEDYNE HASTINGS INSTRUMENTS 804 NEWCOMBE AVENUE HAMPTON VIRGINIA 23669 U S A ATTENTION REPAIR DEPA
46. rugated matrix of flow channels which serve as a shunt The size and number of these channels is consistent with the sensor AP and flow range 3 6 Shunt Theory A flow divider for a thermal mass flow transducer usually consists of an inlet plenum a flow restriction shunt and an outlet plenum See Figure 3 1 Since stability of the flow multiplier is desired to ensure a stable instrument there must be some matching between the linear volumetric flow versus pressure drop of the sensor and the shape of the volumetric flow versus pressure drop of the shunt Most instruments employ Poiseuille s law and use some sort of multi passage device that creates laminar flow between the upstream sensor inlet and the downstream outlet This makes the volumetric flow versus pressure drop curve primarily linear but there are other effects which introduce higher order terms Most flow transducers are designed such that the outlet plenum has a smaller diameter than the inlet plenum This eases the insertion and containment of the shunt between the sensor inlet point and the sensor outlet point However there will be a pressure drop between the sensor inlet and outlet points created by the change in flow passage diameter Since the drop is a square function of the flow velocity the differential pressure will be non linear with respect to flow rate Note also that the pressure drop is a function of density The density will vary as a function of system pressure a
47. s the gain of the closed loop controller Normally this potentiometer will be set at the factory for good stable control It may be necessary to adjust this potentiometer in the field if the system varies widely from the conditions under which the controller was setup Turning this gain potentiometer clockwise will improve stability Turning the potentiometer counter clockwise will speed up the valve reaction time to changes in the command signal Gain Potentiometer Figure 2 9 Manual 152 082010 301 305 306 303 307 Series Page 17 of 35 2 14 Temperature Coefficients As the temperature of the instrument changes from the calibration temperature errors will be introduced into the output of the instrument The Temperature Coefficient of Zero describes the change in the output that is seen at zero flow This error is added in to the overall output signal regardless of Span error vs Temperature 1 496 1 296 y 064 9E 05x 0 0007 1 096 0 8 0 6 0 4 Span Error 96 of Point 0 296 0 0 0 2 Temperature Figure 2 10 flow but can be eliminated by merely adjusting the zero potentiometer to read zero volts at zero flow conditions The Temperature Coefficient of Span describes the change in output after the zero error is eliminated This error cannot be eliminated but can be compensated mathematically if necessary The curve pictured in Figure 2 10 shows the
48. sity 5 times that of air the end effects will become 10 of the total These changes make it impossible to accurately calibrate an instrument on one gas and use it for another gas The pressure drop is linear with respect to the volumetric flow rate between a point that is downstream of the entrance area and another point further downstream but upstream of the exit region For a typical flow divider tube the entry length is approximately 0 16 cm From this it can be seen that if the sensor inlet pickup point is inside of the flow divider tube but downstream of the entrance length and if the sensor outlet point is inside the flow divider tube but upstream of the exit point then the pressure drop that drives the flow through the sensor would be linear with respect to volumetric flow rate Since the pressure drop across the sensor now increases linearly with the main flow rate and the sensor has a linearly increasing flow with respect to pressure drop there is now a flow through the sensor which is directly proportional to the main flow through the flow divider without the flow division errors that are present when the sensor samples the flow completely upstream and downstream of the flow divider Unfortunately a typical shunt has an internal diameter on the order of 0 3 mm This is too small to insert tap points into the tube Also the sample flow through the sensor is approximately 10 sccm while the flow through a shunt is approximately 25 sccm This mea
49. span error in percent of point as a function of temperature assuming 23 is the calibration temperature Manual 152 082010 301 305 306 303 307 Series Page 18 of 35 Theory and Function 3 1 Overall Functional Description The 300 Series flow meters consist of a sensor base shunt control valve 303 307 and electronic circuitry The sensor is configured to measure gas flow rate from 25 10000 slm depending on the customer s desired overall flow rate The shunt divides the overall gas flow such that the flow through the sensor is a precise percentage of the flow through the shunt The flow through both the sensor and shunt is laminar The control valve adjusts the flow so that the sensors measurement matches the set point input The circuit board amplifies the sensor output from the two RTD s Resistive Temperature Detectors and provides an analog output of either 0 5 VDC or 4 20 mA 3 2 Sensor Description The sensor consists of two coils of resistance wire with a high temperature coefficient of resistance 3500 ppm C wound around a stainless steel tube with internal diameter of 0 014 0 36mm 0 017 0 43mm or 0 026 0 66mm and 3 00 7 62 cm length These two identical resistance wire coils are used to heat the gas stream and are symmetrically located upstream and downstream on the sensor tube Insulation surrounds the sensor tube and heater coils with no voids around the tube to prevent any convection losses The ends of
50. ssumed that the heat conducted along the sensor tube from the upstream heater will be equal to the heat conducted through the tube from the downstream heater Similarly the heat Manual 152 082010 301 305 306 303 307 Series Page 19 of 35 conducted from the upstream and downstream coils to the foam insulation surrounding them is assumed to be equal based on the symmetry of the sensor construction Since the sensor tube inlet and outlet are linked by an aluminum ambient bar the high thermal conductivity of the bar provides a thermal short constraining the ends of the sensor tube to be at equal surface temperature Moreover the tube ends and the aluminum ambient bar have intimate thermal communication with the main flow passageway prescribed by the main stainless steel flow meter body This further constrains each end of the sensor tube to be equal to the ambient gas temperature Further since the length of each heater section is nearly 21 times greater than the inside tube diameter the mean gas temperature at the tubes axial midpoint is approximately equal to the tube surface temperature at that point Recall that the outside of the sensor tube is well insulated from the surroundings therefore the tube surface temperature at the axial midpoint is very close to the operating temperature of the heater coils The mean temperature of the gas stream is then approximately the same as the heater temperature Assuming the mean gas temperature is equ
51. ting section can be found in Section 4 3 4 2 Troubleshooting Symptom Cause Action Symptom Cause Action Output reads strong indication of flow with no flow present Zero pot has no effect Power shorted out Turn the power supply off for a few seconds then turn it on again If this is ineffective disconnect the power supply from the unit Check that the power supply voltages are correct Incorrect voltages most likely signify a faulty regulator chip inside the supply If the power supply display returns to zero after the instrument has been disconnected there may be a short from the unit to ground 300 Series instrument output continues to indicate flow with no flow present or indicates 14 volts Power supply inputs are correct see the above troubleshooting tip and zero pot has no effect Faulty IC chip s on the main PC board Replace main PC board See Section 4 5 Symptom Output of flow meter is proportional to flow but extremely small and not correctable by span pot Cause Sensor is not being heated Action Shut off gas supply and disconnect the power to the flow meter Remove cover and PC board from unit Check the resistance from pins 1 to 2 and 3 to 4 of the sensor module Both sets of pins should read approximately the same value between 1 and 2 kQ nominal resistance Also check that the resistance from pins 5 to 6 and 7 to 8 are both nearly the same value between 200 and 400 See Fi
52. tiplied by the GCF for propane divided by the GCF of air 20 0 3499 1 0015 6 9875 To calculate a target setting 20 sccm to achieve a desired flow rate of propane using a meter calibrated to air invert the ratio above and multiply 20 1 0015 0 3499 57 2449 Gas conversion factors can be found at the Hastings Instruments web site http www teledyne hi com Follow the link to Mass Flow Products and then to Gas Conversion Factors Manual 152 082010 301 305 306 303 307 Series Page 35 of 35
53. which attracts the plunger The plunger assembly moves away from the orifice allowing the gas flow to pass between the orifice and the plunger seat The distance between the orifice and the plunger seat and thus the flow through the valve is controlled by the amount of current supplied to the coil The valve seat is made of Kalrez or equivalent perflouroelastomer The valve orifice is made from 316 stainless steel The valve plunger and pole piece are made of nickel plated magnetic alloy Hi perm 49 and the control springs are made of 302 stainless steel The Diaphragm and all seals are as specified per the customer order Viton Neoprene Buna N or Kalrez a Figure 3 3 Manual 152 082010 301 305 306 303 307 Series Page 23 of 35 3 8 Electronic Circuitry The 300 Series flow meters employs a thermal transfer principle capillary tube described in section 3 2 to measure the flow through the sensor which is proportional to the total flow through the instrument The sensor develops a differential voltage output signal proportional to flow which is amplified to produce 5 VDC at full scale flow The amplified output can be measured on pins 6 and 1 of the external D connector If a Hastings power supply is employed the 5 Volt output is also sent to the terminals on the back and to the decoding circuitry in the display which converts it to a numeric output The optional 4 20 mA analog output is available
54. with a dense gas e g Manual 152 082010 301 305 306 303 307 Series Page 7 of 35 sulfur hexafluoride or at high pressures gt 250 psig the instrument must be installed horizontally When mounted in a different orientation the instrument should be re zeroed at zero flow with the system pressurized to the expected operating pressure One of the smallest of the internal passageways in the 300 Series is the diameter of the sensor tube which can be 0 026 0 66 mm 0 017 0 43mm or 0 014 0 36mm so the instrument requires adequate filtering of the gas supply to prevent blockage or clogging of the tube The pressure regulator and the plumbing upstream must be of sufficient size to minimize changes in the upstream pressure When switching from full flow to zero flow the inlet pressure of instrument should rise to no more that 30 above the inlet pressure at full flow In general high capacity regulators and large internal diameter plumbing help to make the system more stable The pressure drop between the regulator and the instrument due to line resistance should be minimized There are two threaded holes located on the bottom of the base that can be used to secure it to a mounting bracket if desired Other holes for special mounting can be added if desired The optional inlet and outlet fittings for the 301 303 are 0 5 0 75 Swagelok 0 5 VCR and 0 5 VCO fittings The O rings for the end cap are Viton optional Kalrez Neoprene or Bun
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