Fluid Components International GF90_GF92 - Manual (Page 41)

Doc. No. 06EN003229 Rev. H 37 GF Series Flow Meter Models GF90/GF92
FLUID COMPONENTS INTERNATIONAL LLC http://www.fluidcomponents.com
Setting Analog Outputs
The flowmeter has two, independent analog signal outputs. The outputs can be set to represent flow rate or
temperature. The flowmeter signal outputs have been configured according to the application information
supplied to the factory at the time of order. However, the outputs can be re-scaled anywhere within the
calibrated flow range. The outputs can be independently set to one of four signal ranges: 4 to 20 mA, 0 to 5
V, 0 to 10 V or 1 to 5 V. A typical configuration is presented in Table 8.
Table 8. Typical Signal Output Configuration
The signal range varies linearly with change in flow rate as shown in Figure 21. Minimum signal output can
be set to indicate a flow of zero. This is often referred to as a zero-based signal output. A minimum signal
that represents a value greater than zero is referred to as non-zero based.
PORT NO. MODE TYPE ZERO FULL SCALE (F.S.)
1 4 TO 20 mA Flow 0 SF/S 150 SF/S
2 4 TO 20 mA Temp -50° F 150° F
Figure 21. Signal Output Versus Flow Rate
NOTE: The flowmeter inherently has a minimum, non-zero flow rate that it is able to detect. Therefore,
setting the minimum signal output (referred to as Zero in Menu 2.1.1) to zero will create a step in
the output. This step corresponds to the flow where the flowmeter begins accurate measurement.
Turndown ratios ( turndown is defined as the maximum flow rate divided by the minimum flow
rate) smaller than 10:1 will have a large step change thus reducing the usable signal range.
To re-scale the signal outputs:
1. From the Main menu press 2. The 2.0 PORT SETUP menu title will appear.
2. Press 1, the Analog Output option.
3. Press 1 or 2, corresponding to the analog port to be re-scaled.
4. After entering the user password (if it is enabled), press 1 to change the analog output
mode. Select the signal mode. (The current selection is shown in parenthesis to the left of the
question mark.)
5. Press 2 to change the analog output type. Press 1 for an output signal based on flow.
Press 2 for an output signal based on temperature.
6. Press 3 to change the maximum or Full Scale (F.S.) flow rate. Enter a maximum flow
rate value within the specified range.
7. Press 4 to change the zero flow rate. Enter a minimum flow rate value within the
specified range. A value of zero is valid.
8. Press 5 to save and exit to the previous menu level. Press Y when asked to save