28
E N G L I S H
D.
Figure 6
Testing Diodes
(Figure 6)
Warning
To avoid damages to the Meter or to the
devices under test, disconnect circuit power and
discharge all the high-voltage capacitors before
testing diodes.
Use the diode test to check diodes, transistors, and
other semiconductor devices. The diode test sends a
current through the
semicondutor junction,
then measure the voltage
drop across the junction.
A good silicon junction
drops between 0.5V and
0.8V.
To test the diode out of a
circuit, connect the Meter
as follows:
1. Insert the red test
lead into the
V
Ω
terminal and the black
test lead into the
COM
terminal.
2. Set the rotary switch to
Ω
and press
SELECT
button to select measurement mode.
3. For forward voltage drop readings on any
semiconductor component, place the red test lead on
the component’s anode and place the black test lead on
the component’s cathode.
Note:
• In a circuit, a good diode should still produce a forward
voltage drop reading of 0.5V to 0.8; however, the
reverse voltage drop reading can vary depending on
the resistance of other pathways between the probe
tips.
• Connect the test leads to the proper terminals as said
above to avoid error display.
• The LCD will display
OL
indicating either open circuit
or wrong polarity connection.
• The unit of diode is volt (V), displaying the forward
voltage drop readings.
• To remove the objects being tested from the circuit
when measuring can obtain a more accurate result.
