Smiths Aerospace
Electronic Systems – Malvern
DOC NO.0134ED
MAINTENANCE MANUAL SUPPLEMENT
BOEING B737-100/200/300/400/500
28-41-04
(d) Measure the capacitance of the tank units.
1) The capacitance must have these values with the applicable tolerance:
TANK
Capacitance (pF)
TOLERANCE (pF)
Left/Right
458.2
±16
Left/Right 474.2
±16
Left/Right
490.6
±16
Left/Right 506.6
±16
Center Integral
164.2
±4
Center 180.2
±4
Center 1 Cell
129.1
±4
Center 1 Cell
145.1
±4
Center 2 Cell
188.5
±4
Center 2 Cell
204.5
±4
Center 3 Cell
164.2
±4
Center 3 Cell
219.4
±4
Aux
94.5
±4
Aux (400 Gal)
110.5
±4
Aux (810 Gal)
109.2
±4
(e) If the capacitance is out of the correct range of values, do the test for the tank units and
compensator (Ref 28-41-21/501).
(f) Set the FUNCTION MEASURE switch (PSD40-1) or set the SELECT switch (PSD60-1, -2) or
the MEGGER SELECT switch (PSD60-2R) to COMP.
(6) Measure the capacitance of the compensator.
(a) Depending on aircraft model, the capacitance must be 39.0 pF +/- 1.2 pF or 40.2 pF with a
tolerance of +/-1.2 pF as determined from AMM.
(7) Return aircraft to normal configuration.
(a) Disconnect and remove FQIS test unit.
(b) Disconnect test harness from airplane wire bundle.
(c) Connect the electrical connector to the rear of the DCTU.
(d) Connect fuel quantity indicator to DCTU and reinstall in pilots’ panel (Fig. 501).
(e) Disconnect and remove TSU jumper harness from airplane wire bundle and tank harness.
(f) Reconnect the TSU J1 and J2 connector plugs.
(g) At P6 Main Power Distribution Panel, close these circuit breakers and remove DO-NOT-
CLOSE tags:
1) FUEL
QTY
2) EP GND FUELING
CONFIG
4.2
Page 520
Dec 18/02
Airplanes with Smiths 2307 Model Fuel Quantity Indicators
with TSU
(SIMMONDS SYSTEM TESTER)
EFFECTIVITY
