Ac/Dc Current Measurements; Resistance Measurements - Extech Instruments EX570 User Manual

AC/DC CURRENT MEASUREMENTS

CAUTION: Do not make 20A current measurements for longer than 30 seconds.
Exceeding 30 seconds may cause damage to the meter and/or the test leads.
1. Insert black test lead banana plug into the negative COM jack.
2. For current measurements up to 4000µA DC, set the function switch to
the µA position and insert the red test lead banana plug into the µA/mA
jack.
3. For current measurements up to 400 mA DC, set the function switch to
the mA position and insert the red test lead banana plug into the
µA/mA jack.
4. For current measurements up to 20A DC, set the function switch to the
10A/HZ/% position and insert the red test lead banana plug into the
10A jack.
5. Press the SELECT button to indicate "DC" or "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. Rotate 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 SELECT 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.
7 EX570-ENG V2.3 3/09