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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, and silicon-controlled rectifiers (SCR), and other semiconductor devices. The
test sends a current through a semiconductor junction, and then measures the junction’s voltage drop. A typical junction
drops 0.5 V to 0.8 V.
To test a diode, proceed as follows:
1. Set the rotary switch to
position, and press blue button ( ) to select diodes testing, and the symbol “ ”will be
shown on the left part of the screen.
2.
Insert the black lead into “
COM
” terminal, and the red lead to into the “
Ω
V
” terminal. The polarity of the black lead
and red lead is “-”and “+” respectively.
Figure3-7.
Diode Test
In a circuit, a similar diode should still indicate a forward bias reading of 0.5 V to 0.8 V; however, the reverse-bias reading
can vary depending on the resistance of other pathways between the probe tips.
Note
In the live diodes testing, the resistance of other pathways and between the probe tips will affect the
reading of reverse-bias voltage.
Testing for Continuity (See Figure3-8)
Warning
To avoid possible damage to the meter or to the equipment under test, disconnect circuit power
and discharge all high-voltage capacitors before testing for continuity.
Continuity is the presence of a complete path for current flow. The continuity test features a beeper that sounds if a circuit is
complete. The beeper allows you to perform quick continuity tests without having to watch the display.
See Figure3-8. Continuity Test
