What are the ways to measure the quality of diodes with a multimeter?

Measure with a multimeterdiodeGood or bad is a simple and effective method. Here are the specific steps:

Measurement steps

1. Prepare a multimeter:

   - Set the multimeter to the "diode" test mode (usually marked with a diode icon).

2. Connect the test line:

   - Connect the red test probe to the positive terminal of the multimeter（+）Connect the black test probe to the negative pole（-）.

3. Measure forward conductivity:

   - Contact the red probe with the anode (positive electrode) of the diode and the black probe with the cathode (negative electrode).

   - If the diode is normal, the multimeter should display a positive value (usually0.5Vreach0.7VThe specific value depends on the type of diode.

   - If displayed as“OL”(Out of range), indicating that the diode may be damaged.

4. Measurement of reverse blocking:

   - Contact the red probe with the cathode of the diode and the black probe with the anode.

   - If the diode is normal, the multimeter should display“OL”The diode does not conduct in the reverse direction.

   - If it displays as a low value (such as a few hundred ohms), it indicates that the diode may be damaged.

matters needing attention

- Polarity: Ensure that the polarity of the probe connection is correct during testing, as diodes have directionality.

- Pre measurement inspection: Before measurement, ensure that the diode is not connected to the circuit to avoid other components affecting the test results.

- Temperature effect: The characteristics of diodes may be affected by temperature, so testing should be conducted at room temperature as much as possible.

conclusion

By following the above steps, you can effectively determine the quality of the diode. If the diode displays normally when conducting in the forward direction, but displays as“OL”This indicates that the diode is good; On the contrary, there may be problems.