Ac Current (Frequency, Duty Cycle) Measurements - Extech Instruments MN62 User Manual

AC CURRENT (FREQUENCY, DUTY CYCLE) MEASUREMENTS
CAUTIONS: Do not make 5A current measurements for longer than 10 seconds. Allow 15
minutes between tests. Exceeding 10 seconds may cause damage to the meter and/or the test
leads.
Before connecting the meter in a series circuit turn off the power supply to the series loop.
Start with the highest range possible if unsure of expected current measurement.
Fuses are provided in the 10A and µA/mA input jacks. Do not connect test leads in parallel to
any circuit when test leads are connected to these jacks.
Pressing the HZ‐% button, while taking AC current measurements, is allowed.
1. Insert the black test lead banana plug into the negative COM jack.
2. For current measurements up to 6000µA AC, 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 600mA AC, 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 10A AC, set the
function switch to the A position 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 neutral side of
the circuit.
Touch the red test probe tip to the "hot" side of the circuit.
8. Apply power to the circuit.
9. Read the current in the display.
10. Press the Hz/% button to indicate "Hz".
11. Read the frequency in the display.
12. Momentarily press the Hz/% button again to indicate "%".
13. Read the % duty cycle in the display.
14. Press the Hz/% button to return to the current‐only measurement.
% Duty Cycle Note: Duty Cycle measurements are AC only for this meter. Measurement
signals must be 'zero crossing' and must reach ‐0.7V for the meter to properly display Duty
Cycle %.
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