Table 3-1. Meter Accuracy Requirements
Meter Test Set (A3)
Electrical test set (A4)
Test Instrument
indication (amps)
indications (4 amps)
Minimum
Maximum
Minimum
Maximum
Meter
Dial
current (uA)
Settings
0.0422
0.0466
9.5
10.5
10
100
0.0376
0.0422
9.5
8.5
9
90
0.0376
7.5
8.5
0.0333
80
8
0.0333
0.0289
7.5
65
70
7
0.0244
0.0289
55
60
6.5
6
0.0200
0.0244
4.5
50
5.5
5
0.0156
0.0200
3.5
4.5
40
4
(2) Position TI controls as follows:
(2) Position METER SELECT switch to DC
(a) ORDERWIRE switch to OFF.
AMPS. Disregard the other switch settings.
(3) Advance meter test set (A3) direct current
(b) BUZZER switch to AB.
(c) DIRECTION switch to AB.
control to obtain full-scale (dial indication of 10)
indication of TI TEST METER.
(d) CAP RES switch to RES.
(4) The meter test set shall indicate as listed on
(e) METER SELECT switch to BRIDGE.
the first line of table 3-1.
(f) PULL BATTERY POWER to ON.
(3) Depress READ switch and adjust
(5) Continue adjusting meter test set direct
DISTANCE TO FAULT control to obtain a null
current control as indicated to obtain values
indication on TEST METER.
specified in table 3-1.
(4) Release READ switch. DISTANCE TO
b. Adjustments. No adjustments can be made.
FAULT (RES) scale indication shall be between
3-3. Meter Accuracy Using Electrical Test
2,300 and 2,500.
Set A4. a. Performance Check.
(5) Disconnect resistor decade and connect
(1) Connect electrical test set (A4) to TI using
capacitance standard (Al) to TI terminals 14 and
adapters as necessary as shown in figure 3-1. (A4
15. Adjust capacitance standard to .05 muF.
is substituted for A3.)
(6) Operate CAP RES switch to CAP.
(2) Position TI DIRECTION switch to BA and
(7) Depress READ control for a null on the TI
METER SELECT switch to DC AMPS. Disregard
TEST METER.
the other switch settings.
(8) Release READ switch. DISTANCE TO
(3) Set the controls of the electrical test set to
FAULT (CAP) scale indication shall be between
measure current. Adjust the coarse, medium, and
1,400 and 1,800.
fine output controls for TI dial settings as listed in
b. Adjustments. No adjustments can be made.
3 - 5 . F i n a l P r o c e d u r e . a . Reenergize and
(4) Observe that the indications obtained are
disconnect TI and all test equipment.
within the specified limits
b. In accordance with TM 38-750, annotate and
b. Adjustments. No adjustments can be made.
a f f i x calibration DA Label 80 (US Army
3-4. Bridge Accuracy. a. Performance Check.
Calibration System). When the TI cannot be
(1) Disconnect the previous meter test set
adjusted within tolerance, annotate and affix red
hookup. Set resistor decade (A2) to 50 ohms.
tag, DA Form 2417 (Unserviceable Test
Connect resistor decade to TI terminals 14 and 15
Instrument or Limited Use Tag).
(BRIDGE binding posts) using leads electrical
(B2) and adapters (B1).
6
