2548H INSTRUCTION MANUAL
56-101-00420 Rev. C
Ch. 3
Nov
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07
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14
Page 30 of 33
(c) Set the EMPTY adjustment for the corresponding system.
(2) Setting “EMPTY” Adjustment (with adapter cable)
CAUTION Ensure Fuel Quantity/Refuel/Defuel power is off while accessing and
before any harness or cable or connector is removed. Maintain power
off while making connections.
(a) Open the appropriate circuit breakers.
(b) Access, and if necessary, remove the amplifier.
(c) Verify the Test Set’s battery condition. (Refer to Battery Test Procedure,
Chapter 3, Section 2.B.)
(d) Place the test equipment in a convenient location and configure the amplifier,
adapter cable, and the aircraft wiring as shown in Figures 16, 17 or 18
according to the system configuration.
(e) Rotate the TEST FUNCTION switch to CAP BRIDGE.
(f) Set TANK CAP pF by entering the EMPTY COMPENSATOR VALUE to be
simulated on the thumbwheel assembly.
Note: If the actual dry capacitance value for the particular aircraft serial
number is known, substitute that value for EMPTY.
(g) Set COMP SIM pF by entering the two left hand digits from step (f) on the
thumbwheel assembly.
(h) Close appropriate circuit breakers.
(i) Press and hold the COMP CAL pushbutton while alternating adjusting
COMP CAL 0-10 and D.F. controls for the lowest possible reading.
(j) Release the COMP CAL pushbutton.
(k) Rotate the TEST FUNCTION selector to CAP SIM 1.
Note: The CAP SIM 2 setting is used with certain ratiometric systems.
(l) Connect the adapter cable and the Test Set’s COAX, TANK and COMP
receptacles as specified for the system-under-test.
(m) Adjust the amplifier E (EMPTY) adjustment to achieve a reading of EMPTY,
ZERO (0).
(n) Set the Test Set’s On/OFF switch to OFF.
(o) If connected, disconnect the adapter cable and the Test Set’s COAX, TANK,
and COMP receptacles.
