TB 9-6625-381-24
9. Capacitance
a. Performance Check
(1) Position controls as listed in (a) through (d) below:
(a)
DIAL CONTROL to 0 on dial drum (RANGE 2).
(b)
SELECTOR switch to CAPACITANCE.
(c)
PERCENT POWER FACTOR control to 0.
(d)
Capacitance range switch to 5 TO 100 MMF (position 2).
(2) If TI meter indication is not below MIDSCALE, perform b below.
(3) Adjust DIAL CONTROL for minimum indication on TI meter. TI dial drum
indication will be within 0.5 pF of 0.
(4) Connect multimeter and 100 pF capacitance standard to TI capacitance binding
posts. Bend adapters 90 degrees to connect capacitance standard to TI binding posts.
(5) Turn DIAL CONTROL throughout its range while observing multimeter.
Indication on multimeter will not exceed 50 V ac. Disconnect multimeter.
(6) Adjust DIAL CONTROL for minimum indication on TI meter. Dial drum of TI
will indicate between 97 and 103 pF. If not reverse connection of capacitance standard to
TI and readjust DIAL CONTROL for minimum meter indication. If dial drum still does
not indicate between 97 and 103 pF, perform b below.
(7) Turn capacitance range switch to 80 to 50000 MMF.
(8) Repeat (4) above.
(9) Turn DIAL CONTROL throughout its range while observing multimeter.
Indication on multimeter will not exceed 20 V ac. Disconnect multimeter.
(10) Adjust DIAL CONTROL for minimum indication on TI meter. Dial drum will
indicate between 95 and 105 pF.
(11) Repeat technique of (10) above using capacitance standard values listed in table 3.
Dial drum will indicate within limits specified. If TI indications are not within limits listed
in table 3, perform b (11) below.
Table 3. 80 to 50,000 MMF Range
Capacitance standard
Test Instrument
values
dial drum indications
(pF)
(pF)
Min
Max
400
380
420
1000
950
1050
2000
1900
2100
5000
4750
5250
10,000
9500
10,500
20,000
19,000
21,000
30,000
28,500
31,500
40,000
38,000
42,000
(12) Turn capacitance range selector switch to .04 TO 30 MF.
