Measuring Frequency And Duty Ratio - Mastech MS2225A Operation Manual

4.17 Measuring frequency and duty ratio

1) Frequency measurement with clamp (at
current gear):
Electric shock.
Remove the probe from the meter before measuring
with the current clamp.
(1) Turn the change-over switch to AC current gear.
(2) Hold the trigger, and open the clamp to clamp one
conductor of measured circuits.
(3) Press the "Hz/%INRUSH/▲"button shortly to switch
into the status of frequency measurement.
(4) Read the frequency value from LCD display.
(5) Press "Hz/%INRUSH/▲"again to enter the status of
duty ratio measurement.
Note:
(1) If two or more circuits of the measured circuits are
clamped, the measurement result will be not correct.
(2)The measurement range of frequency is 10 Hz ~ 1 kHz.
If the measured frequency is less than 10 Hz, the
frequency greater than 10 kHz might be measured, but
the accuracy of measurement cannot be guaranteed.
(3) The measurement range of duty ratio is 10 ~ 95%.
(4) The maximum input current of "
(effective value).
WARNING
" is 1000A AC
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2) At voltage gear:
Electric shock.
Pay special attention to high voltage measurement to
avoid electric shock.
Do not input the voltage with effective value greater
than AC 750.
(1) Insert the black probe into COM jack, and insert the red
probe into INPUT jack.
(2) Turn the change-over switch to AC/DC voltage gear,
press FUNC to enter the status of AC voltage
measurement.
(3) Press the "Hz/%INRUSH/▲"button to switch into the
frequency measurement state.
(4) Connect the probe to both ends of signal source or
load to conduct measurement.
(5) Read on the LCD.
(6) Press "Hz/%INRUSH/▲"again to enter the status of
duty ratio measurement.
Note:
(1) The measurement range of frequency is 10 Hz ~ 10kHz.
If the measured frequency is less than 10 Hz, the LCD
will display "00.0", the frequency less than 10 kHz
might be measured, but the accuracy of measurement
cannot be guaranteed.
(2) The measurement range of duty ratio is 10 ~ 95%.
(3) The maximum input voltage of "
(effective value).
WARNING
" is 750 V AC
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