MA640 Datasheet, PDF (7/12 Pages) Extech Instruments Corporation. – 600Amp AC/DC True RMS Clamp Meter

Diode Test
1. Connect as described for resistance measurements
2. Press the MODE button to select diode test .
3. Touch the test probe tips to the diode or semiconductor junction under test. Note the
meter reading.
4. Reverse the test lead polarity by reversing the red and black leads. Note this reading.
5. The diode or junction can be evaluated as follows:
If one reading displays a value (typically 0.400V to 01.800V) and the other
reading displays OL, the diode is good.
If both readings display OL the device is open.
If both readings are very small or ‘0’, the device is shorted.
Capacitance Measurements
WARNING: To avoid electric shock, discharge the capacitor before measuring.
1. Rotate the function switch to the CAP capacitance position.
2. Press the MODE button to select nF capacitance test
3. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive jack.
4. 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.
5. Read the capacitance value in the display.
Note: For very large values of capacitance measurement time can be
several seconds before the final reading stabilizes.
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MA640 V2.1 07/08