Reference
10
CDM250 User Manual
Checking Diodes
1. Connect the black test lead to the black COM jack.
2. Connect the red test lead to the red V-
jack.
3. Push in the
(ohms) function button.
4. Simultaneously push the 200 and the 2K range buttons to the in
position.
CAUTION.
To prevent damage to the equipment, turn off all power to
the circuit or component being measured.
5. Connect the red test lead to the anode and the black test lead to
the cathode of the diode.
6. Push the POWER button to the ON position. A reading of about
25.0 to 90.0 should appear on the display. Multiply the result by
10 to arrive at the forward voltage drop in millivolts. If the
reading on the display is 1 (overrange indicator), the diode may
be defective (open). If the reading is 00.0, the diode is defective
(shorted).
7. Connect the black test lead to the anode and the red test lead to
the cathode of the diode. A reading of 1 (overrange indicator)
should appear on the display. If any other value is displayed, the
diode is defective. On some diodes the meter might flash a high
number for a very short period of time, but the reading should go
to the overrange indicator.
NOTE
. When the diode being tested is in a circuit where parallel
current paths offer low resistance, the above tests may require
disconnecting one end of the component from the circuit.