Dwyer GFC - Manual (Page 6)

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2. INSTALLATION
2.1 Primary Gas Connections
Please note that the GFC Mass Flow Controller will not operate with liquids. Only
clean gases are allowed to be introduced into the instrument. If gases are con-
taminated they must be filtered to prevent the introduction of impediments into the
sensor.
Caution: GFC 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 Controller is ±15 0 . 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 nec-
essary. It is also preferable to install the GFC transducer in a stable environment,
free of frequent 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 contaminants. 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 until the ends of the properly sized tub-
ings home flush against the shoulders of the fittings. Compression fittings are to
be tightened according to the manufacturer's instructions to one and one quarter
turns. Avoid over tightening which will seriously damage the Restrictor Flow
Elements (RFE's)!
Compression fittings should not be removed unless the meter is being cleaned or
calibrated for a new flow range.
Using a Helium Leak Detector or other equivalent method perform a thorough
leak test of the entire system. (All GFC's are checked prior to shipment for leak-
age within stated limits. See specifications in this manual.)
2.2 Electrical Connection
GFC transducers require a +12VDC (+24VDC optional) power supply with a min-
imum current rating of 1100 mA to operate. The operating power input is supplied
via the 15-pin "D" connector located at the side of the flow transducer enclosure.
On GFC's purchased without an LCD readout, a readout panel meter, digital mul-
timeter, or other equivalent device is required to observe the flow signal.
A built in SETPOINT potentiometer is supplied with all GFC transducers for local
control of the flow. A variable analog 0 to 5 VDC (or 4 to 20 mA) reference input
is required for remote control.