TB 9-6625-047-24
7. Equipment Setup
WARNING
HIGH VOLTAGE is used or exposed during the performance of
this calibration.
DEATH ON CONTACT may result if
personnel fail to observe safety precautions.
REDUCE
OUTPUT(S) to minimum after each step within the
performance check where applicable.
a. Remove protective cover from TI only when necessary to make adjustments. Replace
cover after completing the adjustments.
b. For model 400E, adjust front panel mechanical zero adjustment for a zero indication.
For model 400EL-02, set REL REF adjustment (located in center of RANGE switch) to
ABSOLUTE (fully cw).
c. Set RANGE switch to 10 VOLTS. Connect to an appropriate ac voltage source and
set LINE switch to ON. Allow at least one-half hour for warm-up.
8. Voltage Accuracy
a. Performance Check
(1) Connect voltage divider INPUT (p/o calibrator) to calibrator OUTPUT
terminals and voltage divider OUTPUT to TI INPUT terminal.
(2) Set TI RANGE and calibrator initial output as indicated in table 3. Adjust
calibrator for the TI meter indication specified. Final calibrator Error display indication
will be within the specified limits; if not, perform indicated adjustments.
NOTE
In table 3 below where "--" appears in "Meter indication"
column and "N/A" appears in "Error display indication"
column, a reference point is being established on the TI to be
used in (4) through (8) below. TI accuracy is not being verified
at these points.
Table 3. Range Accuracy
Test instrument
Calibrator
Adjustments
RANGE
Meter
Initial input
Error display indication
fig. (1)
(VOLTS) indication
(R)
Voltage
(+%)
.001
1
1.0 V
1.0
kHz
1.0
A2R44
.001
--
0.9 V
1.0
kHz
N/A1
---
Set calibrator to STANDBY and remove voltage divider from setup
.003
3
3.0 mV
1.0
kHz
1.0
---
.003
--
3.0 mV
1.0
kHz
N/A1
---
.01
1
10
mV
1.0
kHz
1.0
A2R38
.01
--
9.0 mV
10
kHz
N/A1
---
See footnote at end of table.