Omega FMA 5400A - Linearity Adjustment; Open Motorized Valve in FMA 5400 A;5500 A Series Max. Flow 200, 500 and 1000 L;Min; Connections and Initial Warm up; ZERO Adjustment

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See also section (8) TROUBLESHOOTING. If after attempting to remedy the
above conditions, a malfunction still persists, return the meter for factory service,
see section (1). At this point the calibration is complete. However, it is advisable
that several additional points between 0 and 100%, such as 25%, 50%, and 75%
flow be checked. If discrepancies are found, proceed to step 7.3.4 for Linearity
Adjustment.
LIKELY REASONS FOR A MALFUNCTIONING SIGNAL MAY BE:
✓ Occluded or contaminated sensor tube.
✓ Leaking condition in the FMA 5400A/5500A transducer or the gas line and fittings.
✓ For gases other than nitrogen, recheck appropriate “K” factor from Gas Factor Table.
✓ Temperature and/or pressure correction errors.
7.3.4 Linearity Adjustment
All adjustments in this section are made from the outside of the meter, there is
no need to disassemble any part of the instrument.
7.3.4.1 Open Motorized Valve in FMA 5400A/5500A
Series Max. Flow 200, 500 and 1000 L/min
Set the valve to PURGE mode by connecting pin [4] to pin [3], at the 15 pin
D-connector.
7.3.5 Connections and Initial Warm Up
Connect the multimeter to output pins [1] and [2] for 0 to 5 Vdc (or pins [9] and
[14] for 4 to 20 mA) of the 15-pin “D” connector - (see Figure 2-1). If calibration to
a new flow range or different gas is being performed, it may be necessary to
remove any jumpers at J1A, J1B, and J1C before beginning linearizing procedure.
Power up the Mass Flow Controller for at least 30 minutes prior to commencing
the calibration procedure.
7.3.6 ZERO Adjustment
Shut off the flow of gas into the Mass Flow Controller. To ensure that no seepage
or leak occurs into the meter, it is good practice to temporarily disconnect the gas
source. Using the multimeter and the insulated screwdriver, adjust the ZERO
potentiometer [R34] through the access window for 0 Vdc (or 4 mA respectively)
at zero flow.
7.3.7 25% Flow Adjustment
Reconnect the gas source. Using the flow regulator, adjust the flow rate to 25%
of full scale flow. Check the flow rate indicated against the flow calibrator. Adjust
the setting for potentiometer [R33] by using the insulated screwdriver through
the access window, until the output of the flow meter reads 1.25 Vdc ±63mV (or
8mA ±0.25mA).