APPA 506 - Diode Testing; Testing Diodes and Semiconductors

506/506B
EN
Testing Diodes
CAUTION
• To avoid possible damage to the meter or to the equipment
under test, disconnect circuit power and discharge all
highvoltage capacitors before testing diodes.
Use the diode test to check diodes, transistors, silicon
controlled rectifiers (SCRs), and other semiconductor
devices.
This function tests a semiconductor junction by sending a
current through the junction, then measuring the junction's
voltage drop. A good silicon junction drops between 0.5V
and 0.8V.
For forward-bias readings on any semiconductor component,
place the red test lead on the component's positive terminal
and place the black lead on the component's negative
terminal. In a circuit, a good diode should still produce a
forward-bias reading of 0.5V to 0.8V.
For reverse-bias readings on any semiconductor
component, the meter still can measure. In a circuit, a good
diode should still produce a reverse-bias reading of -0.5V to
-0.8V.
The display shows “OL” if the diode is open or short.
To use diode test, turn the rotary switch to resistance
position, then press the function (yellow) button to select
measuring mode.
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