Ac Current Measurements; Resistance Measurements - Extech Instruments EX430-NIST User Manual

AC CURRENT MEASUREMENTS

CAUTION: Do not make current measurements on the 10A scale for longer than 30 seconds.
Exceeding 30 seconds may cause damage to the meter and/or the test leads.
1. Insert the black test lead banana plug into the negative COM jack.
2. For current measurements up to 4000µA AC, set the function switch to
the yellow µA position and insert the red test lead banana plug into the
µA/mA jack
3. For current measurements up to 400mA AC, set the function switch to the
yellow mA position and insert the red test lead banana plug into the
µA/mA jack.
4. For current measurements up to 10A AC, set the function switch to the
yellow 10A range and insert the red test lead banana plug into the 10A
jack.
5. Press the SELECT button to indicate "AC" on the display.
6. Remove power from the circuit under test, then open up the circuit at the
point where you wish to measure current.
7. Touch the black test probe tip to the negative side of the circuit.
Touch the red test probe tip to the positive side of the circuit.
8. Apply power to the circuit.
9. Read the current in the display.

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 green  position.
2. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive  jack.
3. Press the SELECT button to indicate 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.
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