Test zener diodeTest zener diode

With regards to checking the usefulness of a Zener diode, whether you’re a hardware lover or an expert, you’ll need to guarantee it’s in great working condition. In this article, we will investigate two clear yet exceptionally viable techniques for testing a Zener diode. Toward the finish of this aide, you’ll be exceptional to decide if your Zener diode is great, open, or shorted.

Test zener diode
Test zener diode

Testing with an Ohmmeter :

One of the most solid strategies to evaluate the strength of a Zener diode is by utilizing an ohmmeter, which is normally found on a multimeter . This Test zener diode gives important experiences into the diode’s condition and can be performed effortlessly.

Stage 1: Set Your Multimeter to the Ohmmeter Setting for Test zener diode

Start by picking the ohmmeter setting on your multimeter. This setting for Test zener diode permits you to precisely gauge the obstruction of the diode.

Step 2: Proper Orientation Matters

When performing this test, the orientation of the Zener diode is crucial. Ensure that you connect the multimeter leads correctly to get an accurate reading. Place one lead on each of the diode’s leads.

Step 3: Reading the Results for Test zener diode

Now, it’s time to interpret the results of the ohmmeter reading. If the Zener diode is in good working condition, you should observe a specific resistance value depending on its rating. This value indicates that the diode is regulating voltage as expected. If the reading is close to zero or infinite resistance, it suggests that the diode is either open (not conducting) or shorted (conducting in both directions), indicating a defective diode.

Remember to compare your readings with the manufacturer’s specifications for the Zener diode you’re testing to ensure its proper functioning.

Anode-Cathode Diode Opposition Test zener diode:

The Anode-Cathode obstruction test gives important experiences into the soundness of a Zener diode. This is the way to direct this test zener diode:

Prepare Your Ohmmeter: Start by setting your multimeter to the ohmmeter mode.

Probe Arrangement:

Spot the positive test zener diode of the ohmmeter on the anode of the diode (the lead joined to the earthy colored piece of the Zener diode) and the negative test on the cathode (the lead associated with the side of the Zener diode with the dark strip).

Expected Opposition:

In this arrangement, a solid Zener diode ought to show a respectably low obstruction perusing, regularly in the scope of two or three countless ohms. For instance, a reading of approximately 450KΩ is a good indicator.

  1. Cathode-Anode Diode Resistance Test: The Cathode-Anode resistance test complements the Anode-Cathode test and helps verify the Zener diode’s functionality:
  1. Reverse the Probes: Take your ohmmeter and reverse the probes. Now, place the positive probe on the cathode of the diode and the negative probe on the anode of the diode.
  2. Expected Resistance: In this configuration, a healthy Zener diode should exhibit a significantly higher resistance reading, often exceeding 1MΩ. A typical reading could be around 2.3MΩ. In some cases, the multimeter may indicate ‘OL’ for an open circuit due to the exceptionally high resistance.

Interpreting the Results of test zener diode:

A reliable Zener diode should demonstrate a pattern of moderately low resistance in the forward-biased direction (Anode-Cathode) and very high resistance in the reverse-biased direction (Cathode-Anode). If you observe this pattern during the tests, it indicates that the Zener diode is in good working condition.

Open Diode Test: (Test zener diode experiment)

On the off chance that you suspect that a Zener diode may be breaking down, leading an open diode test can assist with validating your intuitions.

Symptoms of an Open Diode:

When a Zener diode peruses high opposition in the two bearings, it demonstrates that the diode is open, and that implies it isn’t directing power as it ought to.

Forward-Biased Resistance:

In a functional Zener diode, the forward-biased resistance should not be very high. High resistance in the forward biased direction suggests that the diode is not regulating voltage correctly.

  • Replacement Required: If your Zener diode exhibits high resistance in both directions, it is a clear sign that the diode is open and should be replaced in the circuit.

Shorted Diode Test: (Test zener diode experiment)

A shorted diode can disrupt the proper functioning of electronic circuits. To identify a shorted Zener diode, perform the following test:

  1. Symptoms of a Shorted Diode: When a Zener diode reads low resistance in both directions, it indicates that the diode is shorted, meaning it is conducting electricity in both directions.
  2. Reverse-Biased Resistance: In a healthy Zener diode, the reverse-biased resistance should not be low. Low resistance in the reverse biased direction implies that the diode is not performing its voltage regulation function correctly.
  3. Replacement Required: If your Zener diode shows low resistance in both directions, it is a clear indication that the diode is shorted and should be replaced in the circuit.

Testing with a Voltmeter:

The voltage measurement test provides valuable insights into the performance of a Zener diode. To conduct this test, follow these steps:

1.         Reverse Predisposition Voltage Supply: To play out this test, you should apply voltage to the Zener diode in turn around predisposition. This implies that the voltage across the diode ought to be higher than its evaluated Zener voltage.

2.         Circuit Arrangement: In the circuit, interface the Zener diode in series with a resistor. For instance, you can interface a 5.1V Zener diode with a 1KΩ resistor. The voltage source ought to be well over the Zener voltage rating; for example, utilize a 9-volt battery.

3.         Expected Voltage Perusing: While estimating the voltage across the Zener diode utilizing a voltmeter, it ought to unmistakably peruse a voltage near the evaluated Zener voltage of the diode. In this model, you ought to notice a voltage close 5.1V.

Interpreting the Results:

A healthy Zener diode, when subjected to reverse bias voltage higher than its rating, should exhibit a voltage reading near its rated Zener voltage. This indicates that the diode is regulating the voltage as expected. If the measured voltage significantly deviates from the Zener voltage rating, it suggests that the diode is defective and may need replacement.


In conclusion, verifying the condition of a Zener diode is vital for ensuring the proper functioning of electronic circuits. The ohmmeter test we’ve discussed here provides a reliable way to determine whether a Zener diode is good, open, or shorted. By following these simple steps and understanding the results, you can confidently assess the health of your Zener diode and replace it if necessary. Stay tuned for the next test method in the following sections of this article.

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