Precision Meter ME-87 A/U

Milltary Precision Meter / Multimeter ME-82 A/U
Signal Corps US Army
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TRIUMPH
Model 380 Voltammeter
This instrument is designed for testing direct current circuits of
medium power equipment operating on less than 150 volts and con-
suming less than 30 amperes. It is a precision instrument, accurate
within 1% of full scale, and it should be handled carefully that this
high degree of accuracy may be maintained.
Measurements of direct current voltages are made at a sensi-
tivity of 100 ohms per volt. There are three voltage ranges and three
amperage ranges. A push-button switch shifts the meter from current
to voltage ranges. The terminal, marked AMPS./VOLTS is com-
mon for both voltage and current measurements. Various ranges of
measurement are selected by connection to plainly marked binding
posts.
Model 380 Volt-Ammeter is magnetically and electrostatically
shielded. It may be used on or near other equipment which is carry-
ing current.
MEASUREMENT OF CURRENT
Position the instrument close to the circuit under test. Use short
flexible connecting wires, not less than 18 gauge. Determine the
polarity of the circuit under test. Connect the AMPS./VOLTS +
binding post to the positive side of the circuit. Connect the other
side of the circuit to the 30 AMPS binding post for initial determi-
nation of the current in the circuit. If the indication is that the 15
AMPS or 3 AMPS range may be used, shift to the indicated range,
by moving the connection for the 30 AMPS binding post to the 15
AMPS or to the 3 AMPS binding post. If the initial connection
caused the pointer of the instrument to move off scale to the left,
it indicates that the polarity of the circuit is reversed. Reverse the
connections to the meter and the pointer will deflect to the right,
on the scale.
METHOD OF READING THE SCALES
A mirror back is provided under the scales. For all readings,
align the reflection of the pointer with the pointer, to correct for
parallax before reading. The scale is divided into 60 minor divisions
and 6 major divisions which are in line with the numbers above 0.