Dwyer GFM - Manual (Page 6)

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CAUTION: GFM TRANSDUCERS SHOULD NOT BE USED FOR MONITORING
OXYGEN GAS UNLESS SPECIFICALLY CLEANED AND PREPARED FOR SUCH
APPLICATION.
For more information, contact your distributor or Dwyer.
Attitude sensitivity of the Mass Flow Meter is ±15. This means that the gas flow
path of the Flow Meter must be horizontal within those stated limits. Should there
be need for a different orientation of the meter, re-calibration may be necessary. It
is also preferable to install the GFM transducer in a stable environment, free of fre-
quent and sudden temperature changes, high moisture, and drafts.
Prior to connecting gas lines inspect all parts of the piping system including fer-
rules and fittings for dust or other contaminant’s.
Be sure to observe the direction of gas flow as indicated by the arrow on the front
of the meter when connecting the gas system to be monitored.
Insert tubing into the compression fittings (except GFM-1145) until the ends of the
properly sized tubings home flush against the shoulders of the fittings.
Compression fittings are to be tightened according to the manufacturer's instruc-
tions to one and one quarter turns. Avoid over tightening which will seriously dam-
age the Restrictor Flow Elements (RFE's)!
Using a Helium Leak Detector or other equivalent method perform a thorough
leak test of the entire system. (All GFM's are checked prior to shipment for leak-
age within stated limits. See specifications in this manual.)
2.2 Electrical Connections
GFM transducers require a +12VDC (+24VDC optional) power supply with a min-
imum current rating of 200mA to operate. The operating power input is supplied
via the DC power jack or the 9-pin “D” connector located at the side of the flow
transducer enclosure. On GFM's purchased without an LCD readout, a readout
panel meter, digital multimeter, or other equivalent device is required to observe
the flow signal.
DO NOT CONNECT 24Vdc POWER SUPPLY UNLESS YOUR GFM METER WAS
ORDERED AND CONFIGURED FOR 24Vdc.
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