TB 9-6625-1493-35
13. Differential Voltmeter AC
Voltage Accuracy
(Reference Level)
a. Performance Check
(2) Position controls as listed in (a) through (d) below:
(a)
RANGE switch to 1.
(b)
NULL switch to TVM.
(c)
Voltage dials to 1.000000.
(d)
Polarity switch to AC.
(3) Set calibrator for an initial 1.0 V, 400 Hz output. Adjust calibrator amplitude
for TI null indication on each successively more sensitive position of NULL switch until
null indication is obtained on the .001 position.
(4) Set NULL switch to TVM.
(5) Measure ac voltage. If AC measurement standard indication is not between
.999445 and 1.000555 V dc, perform b below.
(6) Repeat technique of (3) through (5) above for calibrator initial outputs and TI
setting listed in table 8. If AC measurement standards are not within limits specified,
perform corresponding adjustments, using technique of b below.
CAUTION
Table 8 requires progressive increase in
voltage output
from
calibrator. To avoid damage to TI, ensure TI is set to proper
range before increasing the output from calibrator.