Ac / Dc Current Measurements; Resistance Measurements - Extech Instruments EX330 User Manual

AC / DC CURRENT MEASUREMENTS

CAUTION: Do not make current measurements at 10 Amps 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, set the function switch to the µA position and insert
the red test lead banana plug into the mA/µA jack
3. For current measurements up to 400mA, set the function switch to the mA position and insert
the red test lead banana plug into the mA/µA jack.
4. For current measurements up to 10A, set the function switch to the 10A range and insert the
red test lead banana plug into the 10A jack.
5. Use the MODE button to select AC or DC current. The display will reflect the selection.
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.
Set the function switch to the  position.
1.
2. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive  jack.
Use the MODE button to view the icon on the display
3.
4. Touch the test probe tips across the circuit or component under test. It is
best to disconnect one side of the circuit under test so the rest of the
circuit will not interfere with the resistance reading.
5. Read the resistance in the display.
7 EX330-EN v5.0 06/14