61-101-00435.A1
June 22, 1999
PAGE 2 OF 7
1.
SYSTEM CAPACITANCE MEASUREMENT
1.
Remove power from Aircraft Fuel Quantity System.
2.
Defuel Aircraft as per Aircraft Maintenance Manual
instructions.
CAUTION: Observe all safety precautions.
3.
Gain access to the Signal Conditioner.
4.
Break electrical connection.
5.
Connect the Adapter Harness A/C connector to mating Aircraft
wiring plug.
6.
Do not connect the Adapter Harness to the Signal Conditioner.
7.
Connect the Adapter Harness HI-Z COAX and LO-Z TANK jacks to
the Test Set HI-Z COAX and LO-Z TANK capacitance jacks using
2 each 101-01008 (BNC to BNC) cables.
8.
Place BNC shorting cap on Test Set LO-Z COMP jack.
9.
Connect the GND jack of the Test Set to a good aircraft
ground using the 101-01007 cable.
10.
Set the Test Set ON/OFF switch to ON.
11.
Set the Test Set TEST FUNCTION switch to CAP BRIDGE.
12.
Set the Adapter Harness IND. SELECT switch to A/C.
13.
Depress the PRESS TO MEASURE pushbutton.
14.
Vary the TANK CAP PF thumbwheels to find the best null (as
close to 0
µ
A as possible) on the Test Set meter.
NOTE: Refer to Test Set manual for details.
15.
TANK capacitance shall measure 61.3 ± 1.5 pF (402C, 414A,
421C) or 47.1 ± 1.5 pF (404).
16.
Release the pushbutton.
17.
Set the Test Set ON/OFF switch to OFF.
18.
Disconnect all connections.
19.
Return aircraft to normal configuration.