Dc Voltage Measurements; Ac Voltage, Frequency, Duty Cycle Measurements - Extech Instruments MM750W User Manual

DC VOLTAGE MEASUREMENTS

CAUTION: Do not measure DC voltages if a motor on the circuit is switching ON/OFF.
Large voltage surges may occur that can damage the meter.
1. Set the function switch to the
2. Use the M (Mode) button to select
3. Insert the black test lead banana plug into the negative
COM jack. Insert the red test lead banana plug into the
positive V jack.
4. 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.
5. Read the voltage in the display.
AC VOLTAGE, FREQUENCY, DUTY CYCLE
MEASUREMENTS
WARNING: Risk of Electrocution. The probe tips may not reach the live parts inside
some 240V outlets. As a result, the reading may show 0 volts when the outlet actually
has voltage. Make sure the probe tips are touching the metal contacts inside the
outlet before assuming that no voltage is present.
CAUTION: Do not measure AC voltages if a motor on the circuit is switching ON/OFF.
Large voltage surges may occur that can damage the meter.
1. Set the function switch to the
2. Use the M (Mode) button to select
3. Insert the black test lead banana plug into the negative
COM jack. Insert red test lead banana plug into the
positive V jack.
4. 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. Read the voltage in the display.
5. Press the HZ/% button to indicate 'Hz' and read the
frequency in the display.
6. Press the Hz/% button again to indicate '%'. Read the
duty cycle % in the display.
7. Press Hz/% again to exit.
position.
(DC).
position.
(AC).
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