Technical Data Sheet No. TD9411M Rev.
CAUTION: This product is not intended to be used in life support applications!
TABLE OF CONTENTS 1. UNPACKING THE GFM MASS FLOW METER......................................... 1 1 1.1 Inspect Package for External Damage................................................. 1 1.2 Unpack the Mass Flow Meter............................................................... 1 1.3 Returning Merchandise for Repair....................................................... 2. INSTALLATION........................................................................................ 1 2.
7.3.6 7.3.7 7.3.8 7.4 7.4.1 7.4.2 7.4.3 50% Flow Adjustment.................................................................... 15 75% Flow Adjustment.................................................................... 15 100% Flow Adjustment....................................................................15 LCD Display Scaling.........................................................................15 Access LCD Display Circuit..............................................................
1. UNPACKING THE GFM MASS FLOW METER 1.1 Inspect Package for External Damage Your GFM Mass Flow Meter was carefully packed in a sturdy cardboard carton, with anti-static cushioning materials to withstand shipping shock. Upon receipt, inspect the package for possible external damage. In case of external damage to the package contact the shipping company immediately. 1.
CAUTION: IT IS THE USERS RESPONSIBILITY TO DETERMINE IF THE INSTRUMENT IS APPROPRIATE FOR THEIR OXYGEN APPLICATION, AND FOR SPECIFYING O2 CLEANING SERVICE IF REQUIRED. AALBORG IS NOT LIABLE FOR ANY DAMAGE OR PERSONAL INJURY, WHATSOEVER, RESULTING FROM THE USE OF THIS INSTRUMENT FOR OXYGEN GAS. For more information contact your distributor or Aalborg7. Attitude limit of the Mass Flow Meter is ±15F from calibration position (standard calibration is in horizontal position).
Based on the GFM transducer’s serial number it may require a different power sup-ply voltage. GFM flow meters with serial numbers below 340621-1 may require 12 or 24 Vdc power supplies. Before connecting power supply check the meter power supply requirements label located on the flow meter back cover. If the power supply requirements label states that the power supply requirement is 12 Vdc, do not connect power supply with voltage above 15 Vdc.
IMPORTANT NOTES: In general, “D” Connector numbering patterns are standardized. There are, however, some connectors with nonconforming patterns and the numbering sequence on your mating connector may or may not coincide with the numbering sequence shown in our pin configuration table above. It is imperative that you match the appropriate wires in accordance with the correct sequence regardless of the particular numbers displayed on your mating connector.
FIGURE 2.b - CUTOUT DIMENSIONS FOR LCD PANEL MOUNTING. 3. PRINCIPLE OF OPERATION The stream of gas entering the Mass Flow transducer is split by shunting a small portion of the flow through a capillary stainless steel sensor tube. The remainder of the gas flows through the primary flow conduit. The geometry of the primary conduit and the sensor tube are designed to ensure laminar flow in each branch.
4. SPECIFICATIONS FLOW MEDIUM: Please note that GFM17/37/47/57/67/77 Mass Flow Meters are designed to work with clean gases only. Never try to meter or control flow rates of liquids with any GFM's. CALIBRATIONS: Performed at standard conditions [14.7 psia (1.01 bars) and 70 FF (21.1 FC)] unless otherwise requested or stated. ENVIRONMENTAL (per IEC 664): Installation Level II; Pollution Degree II. ACCURACY: ±1.5% F.S. (optional enhanced accuracy ±1% F.S.). REPEATABILITY: ±0.25% of full scale.
Power input is protected by a 750 mA (GFM models with serial numbers below 340621-1) or 300 mA (GFM models with serial numbers above 340621-1) M (medium time-lag) resettable fuse, and a rectifier diode for polarity protection. WETTED MATERIALS: GFM17/37/47/57/67/77: Anodized aluminum, brass, and 316 stainless steel with VITON7 O-rings seals; BUNA7, EPR or KALREZ7 O-rings are optional. GFM17S/37S/47S/57S/67S/77S: 316 stainless steel with VITON7 O-rings seals; BUNA7, EPR or KALREZ7 O-rings are optional.
FLOW RANGES TABLE I GFM 17 LOW FLOW MASS FLOW METER* TABLE II GFM 37 MEDIUM FLOW MASS FLOW METER* CODE mL/min [N2] CODE L/min [N2] 01 0 to 10 11 02 0 to 20 30 0 to 15 20 03 0 to 50 31 30 04 0 to 100 32 40 05 0 to 200 33 50 06 0 to 500 CODE L/min [N2] 07 0 to 1 08 0 to 2 09 0 to 5 CODE L/min [N2] 0 to 10 40 60 10 TABLE III GFM 47 HIGH FLOW MASS FLOW METER* * Flow rates are stated for Nitrogen at STP conditions [i.e. 70 FF (21.1 FC) at 1 atm].
5. OPERATING INSTRUCTIONS 5.1 Preparation and Warm Up It is assumed that the Mass Flow Meter has been correctly installed and thoroughly leak tested as described in section 2. Make sure the flow source is OFF. Apply power to the unit by plugging the power supply line into the DC power jack (or 9-pin 'D' connector) on the side of the meter. Allow the Mass Flow Meter to warm-up for a minimum of 15 minutes.
5.3 Swamping Condition If a flow of more than 10% above the maximum flow rate of the Mass Flow Meter is taking place, a condition known as “swamping” may occur. Readings of a “swamped” meter cannot be assumed to be either accurate or linear. Flow must be restored to below 110% of maximum meter range. Once flow rates are lowered to within calibrated range, the swamping condition will end. Operation of the meter above 110% of maximum calibrated flow may increase recovery time. 6. MAINTENANCE 6.
6.2.2 GFM 17 models Unscrew the inlet compression fitting of meter. Note that the Restrictor Flow Element (RFE) is connected to the inlet fitting. Carefully disassemble the RFE from the inlet connection. The 50 micron filter screen will now become visible. Push the screen out through the inlet fitting. Clean or replace each of the removed parts as necessary. If alcohol is used for cleaning, allow time for drying. Inspect the flow path inside the transducer for any visible signs of contaminant.
The calibration can then be corrected to the appropriate gas desired based on relative correction [K] factors shown in the gas factor table - see Appendix 2. A reference gas, other than nitrogen, may be used to better approximate the flow characteristics of certain gases. This practice is recommended when a reference gas is found with thermodynamic properties similar to the actual gas under consideration. The appropriate relative correction factor should be recalculated - see section 9.
7.2 Calibration of GFM Mass Flow Meters All adjustments in this section are made from the outside of the meter, there is no need to disassemble any part of the instrument. GFM Mass Flow Meters may be field recalibrated/checked for the same range they were originally factory calibrated for. When linearity adjustment is needed, or flow range changes are being made proceed to step 7.3. Flow range changes may require a different Restrictor Flow Element (RFE).
See also section 8. TROUBLESHOOTING. If after attempting to remedy the above conditions, a malfunction still persists, return the meter for factory service, see section 1.1. At this point the calibration is complete. However, it is advisable that several additional points between 0 and 100%, such as 25%, 50%, and 75% flow be checked. If discrepancies are found, proceed to step 7.3 for Linearity Adjustment. 7.3 Linearity Adjustment 7.3.
7.3.4 10% Flow Adjustment Using the flow regulator, adjust the flow rate to 10% of full scale flow according to the calibrator. Check the flow rate indicated against the flow calibrator. Adjust the setting for potentiometer [R33] by using the insulated screwdriver through the access window, until the output of the flow meter reads 0.5VDC ±63mV (or 5.6mA ±0.25mA). 7.3.
7.4.1 Access LCD Display Circuit Carefully remove the LCD from the GFM or panel mounted surface. Remove the aluminum housing on the side of the connection cable. Slide the LCD assembly out of the aluminum housing. 7.4.2 Adjust Scaling Using a digital multimeter connected to either the 0 to 5 VDC or 4 to 20 mA signal at the 9-pin “D” connector, set the flow rate on the GFM to full scale flow (5 VDC or 20mA).
8.
INDICATION LIKELY REASON REMEDY No zero reading after 15 Embedded temperature has Readjust ZERO minute warm up time and no been changed. potentiometer R34 through flow condition. the access hole (see page 13 for details). No zero reading after 15 Power supply voltage is minute warm up time and no less than 11.0 Vdc. flow condition. Display reading does not response on zero adjustment. Measure voltage on pins 4 and 5 of the 9 pin D-connector. If voltage is less than 11.
INDICATION LIKELY REASON REMEDY LCD Display reading does LCD Display is adjusted for not correspond the correct wrong flow range or flow range according analog engineering units. output 0-5 Vdc signal. Readjust LCD Display scaling for required full scale flow (see 7.4 on page 15). LCD Display reading and analog output 0-5Vdc signal are fluctuate in wide range during the flow measurement. Check external connections to pins 2 and 3 of the D-connector. Make sure the load resistance is more than 1000 Ohm.
INDICATION LIKELY REASON REMEDY LCD Display reading is above maximum flow range and output voltage 0-5 Vdc signal is more than 5.5 Vdc when gas flows through the GFM. Sensor under swamping conditions (flow is more than 10% above maximum flow rate for particular GFM). Lower the flow through GFM within calibrated range or shut down the flow completely. The swamping condition will end automatically. PC board is defective. Return GFM to factory for repair.
INDICATION LIKELY REASON REMEDY GFM is disconnected from the source of the gas (no flow conditions) but LCD Display reading is fluctuating in wide range. Output voltage 0-5 Vdc signal also fluctuating. The power supply voltage is 12 Vdc and stable. Sensor or PC board is defective. Return GFM to factory for repair. Reading on the LCD Display Decimal point jumper is installed in wrong position ten (hundreds) times less on the LCD Display Circuit. or more than actual gas flow.
9. CALIBRATION CONVERSIONS FROM REFERENCE GASES The calibration conversion incorporates the K factor. The K factor is derived from gas density and coefficient of specific heat. For diatomic gases: 1 d X Cp where d = gas density (gram/liter) Cp = coefficient of specific heat (cal/gram) K gas = Note in the above relationship that d and Cp are usually chosen at the same conditions (standard, normal or other).
APPENDIX 1 COMPONENTS DIAGRAM GFM METERING PC BOARD 23
APPENDIX 2 GAS FACTOR TABLE (“K” FACTORS) CAUTION: K-Factors at best are only an approximation. K factors should not be used in applications that require accuracy better than +/- 5 to 10%. ACTUAL GAS K FACTOR Relative to N2 Cp [Cal/g] Density [g/I] .5829 1.0000 .4346 .7310 1.4573 1.205 .6735 .4089 .5082 .8083 .38 .26 .3855 .3697 .3224 .2631 .2994 .324 .291 .7382 .658 .4036 .240 .352 .492 .1244 .1244 .1167 .1279 .1778 .0539 .0647 .1369 .1161 .1113 .3514 .4007 .3648 .336 .374 .2016 .2016 1.162 1.
ACTUAL GAS K FACTOR Relative to N2 Cp [Cal/g] Density [g/I] 1.00 .4357 .1947 .3538 .4252 .2522 .4044 .2235 .4271 .3714 .3896 .2170 .50 .3918 .3225 .3891 .60 .5191 .9784 .4967 .3287 .3538 .3834 .3697 .4210 .4252 .4589 .2031 .2240 .2418 .1760 .5696 .2668 1.454 2.43 2.05 .2421 .1792 1.0106 1.35 1.9 1.722 .508 .15 .1432 .140 .1882 .150 .1604 .224 .366 .3414 .3914 .420 .3395 .3513 .244 .365 .268 .1873 .176 .1357 .1432 .153 .1113 .1654 .140 .1544 .161 .160 .164 .185 .1404 .1071 1.241 1.241 1.241 .1834 .
ACTUAL GAS K FACTOR Relative to N2 Cp [Cal/g] Density [g/I] 1.000 1.000 .764 .9998 .9987 .7893 .80 .2492 .27 .2951 1.453 .7175 .75 .0861 .1912 .3171 .3479 .0545 .1025 .2397 .1108 .3872 .3701 .0593 .5328 .5328 3.610 1.627 1.206 .893 5.707 3.613 1.520 9.90 3.593 2.503 3.739 .715 .715 .5843 .4313 .5835 .6299 .68 .5180 .2499 .2126 .3512 .51 1.46 .990 1.000 .737 .4802 .6134 .7128 .176 .9926 .6337 .446 .2554 .2134 .3950 .174 .4438 .759 .3274 .3547 .1106 .1926 .3221 .2459 .164 .1373 .387 .4343 .246 .2328 .
ACTUAL GAS K FACTOR Relative to N2 Cp [Cal/g] Density [g/I] .36 .3021 .30 .35 .40 .5982 .284 .3482 .69 .2635 .3883 .5096 .3237 .3287 .3278 .1324 .1610 .1250 .399 .366 .3189 .1270 .1691 .1488 .1592 .1543 .127 .182 .1357 .1380 6.843 5.620 6.127 1.967 1.877 1.433 7.580 4.643 2.858 6.516 4.562 4.224 4.64 6.129 6.043 .2031 .161 8.
APPENDIX 3 DIMENSIONAL DRAWINGS 2.38 NO LCD VERSION 0.95 A H FLOW B D E *D *E 6-32 C *C DASHED LINE FOR HIGH FLOW UNITS G F DIMENSION (INCH) MODEL CONNECTION Compression Fitting (except model GFM 77) GFM 17 1/4" Tube O Diameter GFM 37 1/4" Tube O Diameter NO LCD LCD VERSION A B C/*C D/*D E/*E F G H 5.60 1.00 1.00 3.00 5.02 0.69 2.69 4.50 5.98 1.37 1.25 4.13 6.15 0.69 2.69 4.88 GFM 47 3/8" Tube O Diameter 5.98 1.37 1.25 4.13 6.27 0.69 2.69 4.
PARTS OF THE FLOW METER LEFT AND RIGHT VIEWS FRONT VIEW 29
APPENDIX 4 WARRANTY Aalborg7 Mass Flow Systems are warranted against parts and workmanship for a period of one year from the date of purchase. Calibrations are warranted for up to six months after date of purchase, provided calibration seals have not been tampered with. It is assumed that equipment selected by the customer is constructed of materials compatible with gases used. Proper selection is the responsibility of the customer.
TRADEMARKS Aalborg®-is a registered trademark of Aalborg Instruments & Controls. Buna®-is a registered trademark of DuPont Dow Elastometers. Kalrez®-is a registered trademark of DuPont Dow Elastomers. Viton®-is a registered trademark of Dupont Dow Elastomers L.L.C.
