TM 11-6625-444-14-1
S e c t i o n Il. OPERATION UNDER USUAL CONDITIONS
3-5. General
This section contains operating procedures for the
voltmeter. It may be used as a voltmeter or
ratiometer to measure or compare voltages from 0
to 1100V DC. A printer output capability is also
described.
a. Disconnect test leads from INPUT ter-
minals.
b. Set voltmeter controls as follows:
ON
POWER
Fully clockwise
SAMPLE RATE
c. Select VDC and 10V range.
d. Connect a shorting jumper between the HI
and LO INPUT terminals. Verify that GUARD
terminal is connected to LO INPUT terminal.
3-8. DC Voltage Measurement
e. Rotate DC ZERO control to obtain a readout
The voltmeter is capable of measuring voltages
of 00.0000.
from 0 to 1100V DC in four separate ranges (1, 10,
f. Disconnect shorting jumper from INPUT
100, or 1000 volts). Automatic ranging can be
terminals and reconnect test leads (red lead to HI
selected, as desired. Polarity of the voltage is
and black lead to LO).
automatically indicated. If desired, an active
filter can be selected to improve noise rejection.
Operation is as follows:
The following checks can be performed to verify
correct operation of the voltmeter:
a. Perform the preliminary starting procedure
a. Make the equipment connections shown in
NOTE
b. Set the dc voltage source output to zero.
Guarded measurements (para 3-3) should
be considered if the source to be measured
c. Verify that the voltmeter readout is 00.0000.
is suspected of containing induced noise
d. Set the dc voltage source output to 10.0V
DC .
or common mode voltages.
e. Verify t h a t the voltmeter readout is
b. Depress VDC FUNCTION switch and
+10.0000 0.002.
AUTO RANGE switch.
c. Connect test leads to dc voltage source (red
g. Rotate RATIO FULL SCALE control on
to positive side and black to negative).
the voltmeter to obtain a readout of +100.000.
d. Rotate SAMPLE RATE control for desired
sampling rate (two readings a second to one
h. Set the dc voltage source output to - 10.0V
DC by reversing the LO and HI INPUT leads.
reading every 4.5 seconds). DO NOT rotate
control fully counterclockwise or the readout will
i. Verify t h a t t h e v o l t m e t e r r e a d o u t i s
continuously indicate the first sampling of the
+100.000 or that it can be set to this value using
the RATIO FULL SCALE control.
input, regardless of any later change.
j. Set the dc source output to zero and
disconnect input leads.
and polarity of measured voltage. If readout
fluctuates, depress FILT FUNCTION switch to
k. Connect a shorting jumper between the LO
improve noise rejection,
and HI INPUT terminals.
f. If desired, select progressively lower ranges
l. Verify that the voltmeter readout is 000.000.
(i.e., 1000, 10;10, or 1) to maximize resolution in
m. Disconnect shorting jumper and dc voltage
digital readout.
source.
