Ac Voltage (Frequency, Duty Cycle) Measurements - PCE Instruments PCE-ITM 20 User Manual

3.2

AC Voltage (Frequency, Duty Cycle) Measurements

Risk of Electrocution. The probe tips may not be long enough to contact
the live parts inside some 240 V outlets for appliances because the contacts are
recessed deep in the outlets. As a result, the reading may show 0 volts when the outlet
actually has voltage on it. Make sure the probe tips are touching the metal contacts
inside the outlet before assuming that no voltage is present.
Do not measure AC voltages if a motor on the circuit is being switched ON
or OFF. Large voltage surges may occur that can damage the meter.
• Set the function switch to the green VAC/Hz/% position.
• Insert the black test lead banana plug into the negative
COM jack. Insert red test lead banana plug into the positive
V jack.
• 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 main display and the frequency in
the right auxiliary display.
• Press the MODE button to indicate "Hz".
• Read the frequency in the main display.
• Press the MODE button again to indicate "%".
• Read the % of duty cycle in the main display.
• Press EXIT for 2 seconds into the function of AC+DC. Test
DC and AC TRUE RMS.
• When the voltage of VAC>0.2V, the frequency of VAC can
be read synchronously in the right auxiliary display.
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