TB 9-4920-454-24
(8) Repeat (4) and (6) above for 8 . If resistance standard does not indicate
between 7.95 and 8.05 , perform b (5) below.
(9) Repeat (4) and (6) above for 4.21 . If resistance standard does not indicate
between 4.16 and 4.26 , perform b (6) below.
b. Adjustments
(1) Connect multimeter to RESISTANCE CHECK meter terminals, observing
polarity. Adjust resistance standard to 22 . Adjust R13 (fig. 12) ccw. Record multimeter
indication, disregarding polarity sign. Adjust R13 (fig. 12) cw. Record multimeter
indication, disregarding polarity sign.
(2) Determine the mean value of indications recorded in (1) above. Adjust R2 (fig. 12)
to this value, then disconnect multimeter.
and adjust R13 (fig. 12) for a 0 indication on
(3) Set resistance standard to 22
RESISTANCE CHECK meter (R).
and adjust R10 for a 0 indication on
(4) Set resistance standard to 15
RESISTANCE CHECK meter (R).
and adjust R7 for a 0 indication on
(5) Set resistance standard to 8
RESISTANCE CHECK meter (R).
and adjust R4 for a 0 indication on
(6) Set resistance standard to 4.21
RESISTANCE CHECK meter (R).
15. Aircraft Indicator
a. Performance Check
(1) Replace BH-823 adapter with BH-822 adapter in equipment setup shown in
figure 11, and remove resistance standard connection.
(2) Set FUNCTION SELECT switch to A/C IND CHK and RESISTANCE & A/C
INDICATOR CHECK switch to NULL BAL.
(3) Connect multimeter between (+) and (-) eyelets on BH-822 adapter. (If adapter
is for D'Arsonval type indicator, A is (+) and B is (-).)
(4) Turn A/C IND ADJ potentiometer from ccw to cw end while observing
multimeter indications. Range on potentiometer should be approximately 0 to 65 mV dc
and there should be no open spots throughout the range. During this check, with
TEMPERATURE switch set to OPERATE, TEMP oC, indicator should follow setting of
potentiometer and display readings throughout range of ambient temperature to 1399 oC.
(5) Set RESISTANCE & A/C INDICATOR CHECK switch successively to 8 , 15 , and
22
positions. In each of the positions the multimeter will indicate higher values than
when RESISTANCE & A/C INDICATOR CHECK switch is in NULL BAL position.
b. Adjustments. No adjustments can be made.
