Fluid Components International GF90_GF92 - Manual (Page 77)

Doc. No. 06EN003229 Rev. H 73 GF Series Flow Meter Models GF90/GF92
FLUID COMPONENTS INTERNATIONAL LLC http://www.fluidcomponents.com
Condensation, Pulsing Flow or Transient Flow
If a component of the process media is near its saturation temperature it is probably condensing on the
flow element. Liquid on the flow element will drive the flow measurement higher than actual. The flow
element must be placed somewhere else in the process where the flow stream temperature is well above
the saturation temperature and below the saturation pressure of any of the process gases.
Pulsing or transient flows will cause the flowmeter measurement to be higher than actual. Compressors,
fans, blowers, etc. commonly induce pulsation within the flow stream. The flow element should be
located at least 20 diameters downstream and 10 diameters upstream of any compressor, fan or blower.
Transient flow (quick increases or decrease flow rate) may cause an indeterminate amount of error in the
flow measurement. The flow rate measurements made during quick changes in flow rate should be
discarded.
Natural Convection in Vertical Pipes and Ducts
A long, vertical stand of pipe that has no induced flow may have a circulation of gas caused by free
convection. If the flowmeter was calibrated to measure small flow rates the convection current may
cause a flow reading. If this is undesirable, move the flow element to another location.
The Relays
See Chapter 4 for instructions on setting the relays. From the keypad, the relay state can be switched.
This can be used to test the interface with the GF series relays.
To test the relays:
1.
From the Main menu press 2. The "2.0 PORT SETUP" menu title will appear.
2. Press 2, the "Relay Setup" option.
3. Press 3, for the "Test Relays" option.
4. Pressing 1 or 2 will toggle the states of the respective relays. The present state of the
relays are displayed in parenthesis.
The relays toggle between energized and de-energized and the state should be reported in the status
line of the "Normal Operation" window. Changing states also cause an audible click.
Other
Troubleshooting