TM 11-6625-444-14-2
dial-a-volt (A10) to the voltmeter LO INPUT
(2) Apply +190.00 Vdc to the voltmeter IN-
(front) terminal and connect the positive (+) ter-
PUT terminals from the dc voltage calibrator.
minal to the voltmeter LO EXTERNAL REFER-
Observe the display readout.
ENCE terminal. (Refer to figure 6-20.)
(3) Adjust A1-R5 for a display readout of
+190.000 Volts.
(7) Set the dial-a-volt to +1 mV.
h. +1 kV Full Range Adjust (A1-R7)
(8) Adjust the SAMPLE RATE control for
approximately one display readout every sec-
ond.
(1) Select the 1000 V range on the volt-
meter.
(9) Adjust A9-R3 to achieve a reading
half-way between the initial readout observed
(2) Apply +1000.0 Vdc to the voltmeter lN-
and +100.000 (Refer to figure 6-19 for the loca-
PUT terminals from the dc voltage calibrator.
tion of adjustments.)
Observe the display readout.
(10) Adjust A9-R13 for a display readout
(3) Adjust A1-R7 for a display readout of
of +100.000.
+1000.00 volts.
(11) increase the dial-a-volt output to +10
V and observe the display readout.
WARNING
Reduce the dc voltage calibrator out-
(12) if readout increases (i.e. +100.100),
put signal level to below 1 volt before
adjust A9-R13 for a readout negative by the
removing the leads from the voltmeter.
same amount (i.e. +99.900).
(13) Adjust A9-R3 to bring the display
readout back to +100.000.
10 V Full Range (A9-R3)/10 V Dc Common
(14) if readout decreases (i.e. +99.900),
(A9-R13)
a d j u s t A9-R13 for a readout positive by the
s a m e amount (i.e. +100.100).
(1) Set the RATlO FULL RANGE control
(10 turn) to its mechanical center of rotation and
(15) Adjust A9-R3 to restore the display
leave it at this setting.
readout to +100.000.
(2) Select the 20 V range and DC/DC RA-
(16) Reduce the dial-a-volt output to
TIO function on the voltmeter.
T h e display should still indicate
+1
mV.
+ 1 0 0 . 0 0 0 ( 000.010). If it does not, repeat
steps (9) through (14).
(3) Connect a dc voltage calibrator (A1) to
the voltmeter HI/LO INPUT (front) terminals.
See figure 6-20.
(17) Disconnect all equipment connections
from the voltmeter.
(4) Connect a second dc voltage calibra-
tor (A1) to the voltmeter V/LO EXTERNAL REF-
ERENCE terminals.
b. 60 Hz Common Mode Adjustments (A9-C4,
C7)
(5) Apply -10.00 Vdc signals from both dc
voltage calibrators to the voltmeter.
(1) Connect a shorting jumper (B7) be-
tween the V and LO EXTERNAL REFERENCE ter-
minals on the voltmeter.
(6) Connect the minus (-) terminal of the
