Digital multimeter diode range and diode measurement method
Illustration of the diode setting of the digital multimeter and the diode measurement method. When you turn the digital multimeter to the diode setting to measure the diode, some data will appear. What do these data mean?
The diode gear is a gear that is frequently used. This gear is generally found on digital meters. The mark is a diode symbol, and there may be a symbol similar to "signal" around it. For details, please refer to the picture above. Representation mode.
Rotate the multimeter to this position and see if the display shows the "signal" symbol mentioned above (refer to the picture above). In fact, this is the buzzer position. If you short-circuit the red and black test leads, you will hear The sound of the buzzer can be used to measure the continuity of the wire, but today we are talking about another one. Press the switch key on the digital meter and you can see a diode symbol displayed on the display.
Since the red test lead of the digital meter is connected to the positive pole of the internal power supply, and the black test lead is connected to the negative pole of the internal power supply, when measuring a diode with a digital meter, the red test lead is placed on the positive pole of the diode, and the black test lead is connected to the negative pole of the diode. Under normal circumstances, the display screen The forward voltage drop of the diode will be displayed. For example, the diode voltage drop in the picture below is 0.607 volts.
For normal diodes, the conduction voltage drop can be measured, but if the diode is reversed (the red test lead is connected to the cathode of the diode, and the black test lead is connected to the anode of the diode), no results can be measured. Therefore, this method can also be used to judge the quality of the diode. Bad, please refer to the measurement results in the picture below for details.
The above figure uses ordinary rectifiers as an example to measure diodes. In fact, this method can basically be used for other types of diodes. For example, this gear can also be used to measure the conduction voltage drop of LED lights (light-emitting diodes).
