Valve Adjustment; Valve Adjustment For Series Max. Flow 10, 50, 100 L/Min; Close Loop Full Scale Flow Adjustment; 10% Close Loop Flow Adjustment (Using R33 Potentiometer) - Omega FMA 5400A User Manual

should read 5.00VDC ±63mV (or 20mA ±0.25mA). If the reading is outside of that
range, place the jumper at [J1C] as appropriate to increase or decrease the sig-
nal. Adjust the setting for potentiometer [R40] by using the insulated screwdriver
through the access window, until reading is within specification.
Repeat steps 7.2.7 to 7.2.10 at least once more.
7.2.13

VALVE ADJUSTMENT

7.2.13.1 Valve Adjustment for
FMA Series Max. Flow 10, 50 and 100 L/min
Discontinue the PURGE mode (set valve for the closed position). Apply an inlet
pressure of 5 psig, and atmospheric pressure at the outlet. If a small flow occurs,
turn the set screw on top of the solenoid valve clockwise until the flow through the
FMA 5400A/5500A just stops.
7.2.14

Close Loop Full Scale Flow Adjustment

Fully open the flow regulator upstream of the FMA 5400A/5500A. Increase the
inlet pressure to 20 psig (25 psig for FMA Series Max. Flow 100 L/min). Apply a
+5.00 VDC (100% full scale flow) setpoint reference. Using the calibrator check
the flow rate. If necessary, adjust R33 to match the desired full scale flow rate. [In
control mode, turning R33 clockwise will decrease the flow. Conversely, turning
R33 counterclockwise will increase the flow through the FMA 5400A/5500A.]
7.2.15 10% Close Loop Flow Adjustment
(using R33 potentiometer)
If the J1A jumper is not installed in upper or lower position (paragraphs
7.2.8 and 7.2.9 were skipped) then skip this paragraph and paragraph 7.2.16.
Proceed directly to paragraph 7.2.17. Change the setpoint to 0.5 Vdc to control
at 10% of full scale flow. Check the flow rate indicated against the flow calibrator.
If the flow is not within ±0.75% of full scale, re-adjust the setting for potentiome-
ter [R33], until the flow output is correct.
7.2.16 25% Close Loop Flow Adjustment
(using R52 potentiometer)
Change the setpoint to 1.25 Vdc to control at 25% of full scale flow. Check the flow
rate indicated against the flow calibrator. If the flow is not within ±0.75% of full
scale, re-adjust the setting for potentiometer [R52], until the flow output is correct.
7.2.17 Close Loop 25% Flow Adjustment
(using R33 potentiometer)
Change the setpoint to 1.25 VDC to control at 25% of full scale flow. Check the
flow rate indicated against the flow calibrator. If the flow is not within ±0.75% of
full scale, re-adjust the setting for potentiometer [R33], until the flow output is cor-
rect.
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