TB 9-6625-1866-50
b. Specifications
AN/USM-98 (J-F 801 AND J-F 801R):
Input requirement1
100 to 130 vac, 60 Hz, 60 w
0.01% for change in line voltage (105 to 130 v); 0.01% per
Stability of reference supply
1
hour after warm-up (adjustable via front panel CAL
control).
As a differential voltmeter:
Input voltage ranges
0 to 500 vdc in 4 ranges
0.05% from 0.1 to 500 vdc (0.1% of input voltage or 0.05
Accuracy
mv whichever is greater below 0.1 vdc.
0 to 10, 0 to 1, 0 to 0.1 and 0 to 0.01 vdc
Null voltage ranges
Dc input resistance
Infinite at null (all ranges).
1
As a vacuum tube voltmeter:
Basic input voltage ranges
0 to 500 vdc in 4 ranges
4% of full scale (all ranges).
Accuracy
Additional voltage ranges
0 to 0.01, 0 to 0.1, 0 to 1, and 0 to 10 vdc.
2
AN/USM-98A and AN/USM-98B (J-F 801B, 801BR, and 801B/AG):
115 or 230 vac, 10%, 50 to 440 Hz, approx. 70w. (801B and
Power input requirements
B/AG, S/N 123 to 1632, operate only on power-line
frequencies of 50 to 60 Hz).
0.5% of full scale for 10% line charge.
Stability of meter zero1
As a differential voltmeter:
Input voltage ranges
0 to 500 vdc in 4 ranges
0.05% from 0.1 to 500 vdc (0.05% +50v) below 0.1 vdc.
Accuracy
0 to 10, 0 to 1, 0 to 0.1 and, 0 to 0.01 vdc.
Null voltage ranges
Dc input resistance
Infinite at null (all ranges).
As a vacuum tube voltmeter:
Basic input voltage ranges
0 to 500 vdc in 4 ranges.
3% of full scale (all ranges).
Accuracy
Additional voltage ranges
0 to 0.01, 0 to 0.1, 0 to 1, 0 to 10 vdc.
2
c. Calibration
Time required
3 hours (approx.)
Technique
Dc and low frequency
-------------------------------------------------------------------------------------
1 This
specification is for information only and is not necessarily verified in this bulletin.
These range are obtained by setting NULL switch to desired range and readout dials to zero.
2
4. General Instructions
annotate DA Form 2416 in accordance with TM 38-750.
801R) will be referred to as UUT (unit under test) in section II. Differential voltmeters
3
