Extech Instruments MultiTec MT310 User Manual page 11

AC or DC Current Measurements
CAUTION: Do not make current measurements on the 20A 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 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
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
into the mA-µA jack.
4. For current measurements up to 20A AC, set the function switch to the "20A" position and insert the red test lead
into the 20A jack.
5. Press the DC/AC key until "AC or DC" appears on the display.
6. Remove power from the circuit under test and open 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 and 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.