How to measure the quality of a diode with a multimeter

Date：2023-06-30 14:24:57Views：300

Diodes are a common electronic component that has a single conductivity and plays an important role in circuits. When electronic engineers carry out circuit maintenance and troubleshooting, they often need to measure the diode to determine whether it is good or bad. The following are the methods and precautions for measuring diodes with a multimeter.

Measure the forward resistance of the diode

Using a multimeter to measure the forward resistance of the diode can preliminarily determine whether the diode is good. The specific operation is as follows:

(1) Connect the black lead of the multimeter to the positive pole of the battery and the red lead to the drain of the diode (i.e. the negative pole of the tube).

(2) Press the pen switch, and the number displayed on the multimeter should be a small number, such as 0.01 or 0.1.

(3) If the multimeter displays a large number, such as 10 or 100, it indicates that the diode has been damaged.

Measure the reverse resistance of the diode

Using a multimeter to measure the reverse resistance of a diode can further determine whether the diode is good. The specific operation is as follows:

(1) Connect the black lead of the multimeter to the negative pole of the battery and the red lead to the source pole of the diode (i.e. the positive pole of the tube).

(2) Press the pen switch, and the number displayed on the multimeter should be a larger number, such as 1 or 10.

(3) If the number displayed on the multimeter is very small, such as 0.1 or 0.01, it indicates that the diode has been damaged.

Measure the voltage of the diode

The normal voltage of the diode can be measured using a multimeter. The specific operation is as follows:

(1) Connect the black lead of the multimeter to the positive pole of the battery and the red lead to the drain of the diode (i.e. the negative pole of the tube).

(2) Adjust the gear of the multimeter so that the voltage between the probes is 0 volts.

(3) Press the pen switch, and the number displayed on the multimeter should be a smaller number, such as 0.01 or 0.1.

(4) If the multimeter displays a large number, such as 1 or 10, it indicates that the diode has been damaged.

Precautions:

1. Pay attention to the polarity of the diode

Diodes have a single conductivity, so when conducting diode measurements, it is necessary to pay attention to the polarity of the diode. Connect the positive pole of the multimeter to the positive pole of the diode, and connect the negative pole of the multimeter to the negative pole of the diode in order to measure the forward conduction voltage. When measuring the reverse cutoff voltage, it is necessary to connect the positive pole of the multimeter to the negative pole of the diode and the negative pole of the multimeter to the positive pole of the diode.

2. Pay attention to the testing mode of the multimeter

When conducting diode measurements, it is necessary to select the diode testing mode of the multimeter. Usually, the diode test mode of a multimeter is labeled as "diode" or "D". After selecting this mode, the multimeter can perform forward and reverse diode conduction tests.

3. Pay attention to the accuracy of the multimeter

When conducting diode measurements, it is necessary to pay attention to the accuracy of the multimeter. If the accuracy of the multimeter is not high enough, it may lead to inaccurate measurement results, which can affect fault location and component judgment.

4. Pay attention to the aging and damage of the diode

Some diodes may age or be damaged during use, so it is necessary to pay attention to the aging and damage of the diodes when conducting diode measurements. If the diode ages or is damaged, it may lead to inaccurate measurement results, which can affect fault location and component judgment.

The above is an introduction to diode measurement. If you have any needs in this regard, please feel free to consult Chuangxin Testing! Measuring diodes with a multimeter is one of the essential skills for electronic engineers. However, when measuring diodes, attention should be paid to the above aspects to ensure the accuracy of measurement results and fault location.