Testing Diodes - SEFRAM BK390B User Manual

Testing Diodes

CAUTION

To avoid possible damage to the meter or to the equipment
under test, disconnect circuit power and discharge all high-
voltage 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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