Fluid Components International GF03 - Manual (Page 49)

Doc. No. 06EN003352 Rev. B 4 5 Model GF03 Flow Meter
FLUID COMPONENTS INTERNATIONAL LLC http://www.fluidcomponents.com
Other
Troubleshooting
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 3 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.
NOTE: Be sure to use the
∆
R table supplied with this flowmeter. Use two decade
resistance boxes, and or fixed resistors.
A
∆
R table is supplied with each flowmeter. The table can be used to verify correct operation
of the transmitter independent of the flow element by simulating the RTDs' input with
precision resistance decade boxes. In order to verify that the flow transmitter is functioning
properly, the inputs from the RTDs may be disconnected and precision resistance of known
value substituted. Then measure the flow transmitter output (voltage, current, or relay logic
switch points) and compare to the Delta R table. Perform the following steps to verify
operation.
1. Verify that the serial number of the flowmeter and the serial number of the Delta R Data
Sheet are the same before proceeding. If the serial numbers do not match, the Delta R
Data Sheet is not applicable. Each flowmeter has a unique Delta R Data Sheet.
2. Verify the Delta R Data Sheet has the appropriate group number.
3. Disconnect JP3 and connect the decade boxes as shown in Figure 27.
Verifying
Delta R’s