TM 1-1520-238-T-7
Change 5
10–160.13
10–48A.
FUEL QUANTITY SYSTEM – CAPACITANCE AND INDICATING TEST
10–48A
(USING PSD 60-1AF TEST SET) (cont)
Task
Result
NOTE
The PSD 60-1AF test set indicates “over range” above 10,000 megohms by
flashing three colons and displaying four zeros.
e. Allow test set (fig. 10–70.5) to stabilize for
30 seconds. Verify test set LCD INDICATOR
displays greater than 20 megohms.
f. Rotate SELECT switch to the following
positions and verify test set LCD indicator
displays greater than one megohm in each
position. LOZ-SHLD, HIZ-SHLD,
SHLD-GND, LOZ-GND and HIZ-GND.
If LOZ and HIZ values are not within required
tolerance, go to paragraph 10–47.
g. Detach T cable (fig. 10–70.7) #2/AFT LOZ
and HIZ leads from TANK UNITS LOZ and
HIZ receptacles.
h. Attach T cable #2 AFT LOZ lead to
INDICATOR LOZ receptacle.
i. Attach T cable #2 AFT HIZ lead to
INDICATOR HIZ receptacle.
NOTE
Do not attach T cable #2/AFT CP lead.
j. Set test set FUNCT switch to MEASURE
INT.
k. Set test set SELECT switch to TU.
l. Set test set TU SIMULATOR decade to 003.
m. Adjust test set TU SIMULATOR vernier
knob until LCD indicator displays 49.4 pf.
If adjusted capacitance value is not within required
tolerance, replace test set.
n. Set test set FUNCT switch to AIRCRAFT
ONLY.
o. Attach T cable connector P1 to fuel signal
conditioner (A308)J1.
p. Select 0–10 VDC scale on multimeter.
Select multimeter to ON.
q. Attach multimeter leads to receptacles on T
cable. Attach multimeter positive lead to T
cable + receptacle. Attach multimeter
negative lead to T cable – receptacle.
