Resistance Measurements; Continuity Check - Extech Instruments MM750W User Manual

RESISTANCE MEASUREMENTS

WARNING: To avoid electric shock, disconnect power to the unit under test and
discharge all capacitors before taking any resistance measurements. Remove the
batteries and unplug the line cords.
1. Set the function switch to the Ω position.
2. Insert the black test lead banana plug into the negative COM
jack. Insert the red test lead banana plug into the positive Ω
jack.
3. Press the M button to indicate Ω on the display.
4. Touch the test probe tips across the circuit or part under test.
It is best to disconnect one side of the part under test so the
rest of the circuit will not interfere with the resistance
reading.
5. Read the resistance in the display.

CONTINUITY CHECK

WARNING: To avoid electric shock, never measure continuity on circuits or wires that
have voltage on them.
1. Set the function switch to the
2. Insert the black lead banana plug into the negative COM
jack. Insert the red test lead banana plug into the positive
jack.
3. Press the M button to indicate
4. Short press the REL button to null any stray resistance.
5. Touch the test probe tips to the circuit or wire under test.
6. If the resistance is less than approximately 50 ohms, an
audible tone will sound. If the circuit is open, the display
will indicate 'OL'.
position.
and Ω on the display.
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