MA640 Datasheet, PDF (8/12 Pages) Extech Instruments Corporation. – 600Amp AC/DC True RMS Clamp Meter

Frequency and Duty Ratio Measurements
1. Rotate the function switch to the Hz Position.
2. Press the MODE button to select AC Voltage
3. Press the HZ % button to select HZ
4. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive Hz jack.
5. Touch the black test probe tip to one side of the device.
Touch the red test probe tip to the other side of the device.
6. Read the Frequency value on the display.
7. Press the HZ % button to select %
8. Read the Duty Ratio on the display.
Type K Temperature Measurements
1. Rotate the function switch to the Temp position.
2. Press the MODE button to select °F or °C.
3. Insert the Temperature Probe into the input jacks.
4. Place the temperature probe tip where needed.
5. Read the temperature on the display.
Note: In case of an open input or a temperature overrange, the meter will
display “OL”.
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MA640 V2.1 07/08