CAUTION
Since overcharging decreases battery life, it is
recommended that the batteries be charged for less
than 48 hours. When used properly, the batteries will
give
more
than
200
charge-discharge
cycles
of
operation.
4.
In the absence of an input signal, the meter should indicate zero.
If
it does not, the meter circuits would be adjusted as follows:
a. With the input power disconnected for a least 3 minutes, the meter
needle is set to zero with the mechanical zero control (fig 5-8).
b. The instrument is turned on and allowed to warm up for 5 minutes.
c. The RANGE switch is set to 1, the voltage readout dials to 0, and
the NULL switch to 0.0001.
d. The INPUT post is shorted to the COMMON post and the electronic ZERO
control is adjusted with a screwdriver for zero meter deflection.
e. The short is removed from the INPUT and COMMON posts.
5.
When operating the instrument as a conventional voltmeter (NULL switch
at TVM) four input-voltage ranges are available. They are 1, 10, 100, and
1000 volts, and are selected by the RANGE switch. Additional lower-voltage
ranges are available by operating the instrument as a differential voltmeter
with the voltage readout dials set to 0.
In this case, the NULL switch
determines full-scale meter calibration.
a. The desired full-scale deflection is selected with the RANGE switch.
b. The NULL switch is set to TVM.
c. The polarity switch is set to + or ac as desired.
d. The unknown voltage is connected to the INPUT and COMMON terminals.
If one side is grounded, it is connected to the COMMON terminal.
e. The voltage magnitude is read on the meter scale.
A positive
voltage at the INPUT terminal will deflect the meter needle to the right.
6.
When operating the instrument as a DC differential voltmeter, a dc
differential voltmeter measurement can be performed more quickly if the
order of magnitude of the unknown voltage is known at the outset.
If
unknown, it can be quickly measured in the TVM mode as described in
paragraph 5. To measure the unknown voltage, the following procedure would
be followed:
a. Correct meter zeroing is verified as in paragraph 4.
b. The RANGE switch is set to the lowest range setting that includes
the unknown voltage magnitude.
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