Test a zener diode with multimeter

Zener diode is a one kind of diode but it is different from basic diode in detail and application. Here it will focus only testing a zener diode with multimeter. Test example will present for digital multimeter , analog multimeter , including multifunction tester. You can compare the testing which use different tester.

The black stripe indicate Kathode terminal

Step to test a zener diode with multifunction tester.

1. Insert the Anode terminal to A socket and Kathode terminal to K socket.

2. Press the button to start the test process and the tester will display zener diode voltage. Multifunction tester TC1 can detect zener voltage range 0.01-30V

Step to test a zener diode with digital multimeter.

1. Set the range switch to diode test , this range multimeter will supply 2.8VDC from test lead. Test current will flow through a zener diode.

2. Forward bias to a zener diode , good zener diode will display some voltage drop across it which is as same as basic diode test.

Forward bias , black test lead to Kathode and the red test lead to Anode , For a good zener diode , meter will display voltage drop across zener diode which is as same as basic diode test.

3. Reverse bias to a zener diode , a good zener diode will display 2 case it depend on zener diode voltage. It will display OL if zener voltage above 2.8V ( 2.8V is test voltage from multimeter).

and it will display the measured zener voltage if a zener voltage is lower than 2.8V.

Reverse bias to a zener diode , a good zener diode will display OL (zener voltage above 2.8V)

Reverse bias to zener diode , a good zener diode will display measured zener voltage if a zener voltage is lower than 2.8V.

4. Bad zener diode , a shorted zener diode meter will display 000V for forward biasing and reverse biasing.

5. Bad zener diode , an open zener diode meter will display OL for forward biasing and reverse biasing.

Step to test a zener diode with analog multimeter.

Analog multimeter will supply 3VDC from the test lead when setting range to Rx1 , Rx10 , Rx100, Rx1K . The polarity of test leads , the red test lead is negative and the black test lead is positive (+3VDC) , why was this , it's because internal AA battery connection with the test leads.

1. Turn the range switch to Rx10 for small zener diode.

2. Forward bias to a zener diode ; the red test lead to Kathode terminal and the black test lead to Anode terminal. A good zener diode will present some voltage drop across it which is as same as basic diode test.

Forward bias to a zener diode , red test lead to kathode and black test lead to anode.

Forward bias to a zener diode , red test lead to kathode and black test lead to anode.

3. Reverse bias to a zener diode ; the red test lead to Anode terminal and the black test lead to Kathode terminal. A good zener diode will present 2 case it depend on a zener diode voltage.

Reverse bias to a zener diode ; the red test lead to Anode terminal and the black test lead to Kathode

A good zener diode , the pointer point at ∞ Ohm.

Reverse bias to a zener diode ; the red test lead to Anode terminal and the black test lead to Kathode

A good zener diode , the pointer indicate measured zener voltage , in case of zener voltage is lower than 3VDC ( 3VDC is test voltage from the test leads)

4. Bad zener diode , a shorted zener diode , the pointer will always point at 0 Ohm. It is still point at 0 Ohm when switching test leads.

5. Bad zener diode , an open zener diode , the pointer will always point at ∞ Ohm. It is still point ∞ Ohm when switching test leads.