Test a zener diode with Digital multimeter Analog multimeter and multifunction tester.

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.


Test   Zener  Diode
                                 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


Test  Zener  Diode


Test   Zener  Diode



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.

Test  Zener  Diode
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.


Test   Zener  Diode
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.


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



Zener  Diode  Test
   
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.



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



Check  Zener  Diode
   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.

Test  Zener  Diode
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.


Test  Zener  Diode
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.


                          A  shorted  zener diode , the pointer will  always  point  at 0 Ohm.

Test  Zener  Diode

                       Open zener diode  , the pointer will  always  point at  ∞  Ohm