ADInstruments AD71B Manual De Usuario página 57

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Black
Red
Figure 3-5. Diode Test
Warning
To avoid harms to you, please do not attempt to input voltages higher than
60V DC or 30V rms AC.
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, set up the Meter as Figure 3-5 and proceed as follows:
1. Insert the red test lead into the
terminal.
2. Set the rotary switch to
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. The red test lead polarity is "+" while the black test lead
polarity is "— ".
The measured value shows on the display.
The BLUE button cycles among resistance, continuity, and diode.
Note
z In a circuit, a good diode should still produce a forward voltage drop reading of
0.5V to 0.8V; however, the reverse voltage drop reading can vary depending on
the resistance of other pathways between the probe tips.
z Connect the test leads to the proper terminals as said above to avoid error display.
z The LCD will display OL indicating either open circuit or wrong polarity connection.
z The unit of diode is volt (V), displaying the positive-connection voltage-drop value.
z Open circuit voltage approximate 2.8V.
©Copyright Abacanto Digital SA.
terminal and the black test lead into the COM
; and press BLUE button to select
Manual de usuario AD71B
AD Instruments
measurement
57