Current Measurements - Sperry instruments DM-4400A Operating Instructions Manual

CURRENT MEASUREMENTS

Sec. 9.2
1. Insert the black and red test leads into the respective "COM"
and "10A" terminals.
2. Place the function switch to the 10A position. Always start with
the highest range of the function to be measured.
The 10A range is unprotected and has a very low internal resistance. Do
not attempt to take a current measurement if the current is unknown or
above 10Adc. The "COM" terminal potential should not exceed 500V
measured to ground.
3. Completely de-energized the circuit in which the current is to be
measured. Place the DMM in series with the conductor carrying
the current, which is to be measured. Energized the circuit.
4. If the reading is less than 0.20 Amps, you can switch to a lower
range for greater accuracy. If not, you have completed your
measurement and skip to step 7.
Before changing ranges, always de-energize the circuit completely. An
open circuit exists between the test leads during range change on the
DMM.
5. To change to a lower range, move the red test lead to the "mA"
jack on the DMM and switch the range selector switch to the
"200mA" position.
The mA ranges are fuse protected. To avoid possible electrical
shock, instrument damage and/or equipment damage do not:
1. Attempt to take mA current readings on circuits having more
than 0.2A current flow.
2. Impress a voltage between the "COM" and "mA" terminals
exceeding 250Vac/dc. Some circuit damage may result for
voltages below 250Vac/dc
CAUTION
CAUTION
CAUTION
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