User's Manual

3000 FC
Users Manual
24
Diode Test
 Warning
To prevent possible electrical shock, fire, or
personal injury, disconnect power and
discharge all high-voltage capacitors before
you measure resistance, continuity,
capacitance, or a diode junction
Do a diode test on diodes, transistors, silicon controlled
rectifiers (SCRs), and other semiconductor devices. The
function sends a current through the semiconductor
junction and then measures the voltage drop across the
junction. A good silicon junction drops between 0.5 V and
0.8 V.
To do a diode test on a diode out of circuit, set up the
Product as shown in Figure 8. For forward-bias
measurements on a semiconductor component, put the
red test lead on the positive terminal of the component
and put the black test lead on the negative terminal of the
component.
In a circuit, a good diode has a forward-bias
measurement of 0.5 V to 0.8 V. A reverse-bias
measurement includes the resistance of other pathways
between the probes.
A short beep sounds if the diode is good (<0.85 V). A
continuous beep sounds if the measurement is ≤0.100 V
or short circuit. The display shows “OL” if the diode is
open.