Testing Transistors With Digital and Analogue Multimeters.

[HellasTechn]

Hello !

I have a silly question of which the answer i am sure is simple. Why when testing transistors with DMM we put positive probe to P side and negative to N side while with AMM we go reverse (negative to P side and positive to N side) ?

Thank you !

 

[BobK]

What settings are you using on the multimeters? If using a diode check setting, it should be + to P - to N, but if using a resistance setting, the opposite.

Bob

 

[duke37]

Because of the circuit in the analog meter, The red lead is negative. Doubtless this simplifies the switching.

 

[HellasTechn]

I use the diode mode for the DMM and resistor mode (usually mid scale like x10 or x100) for AMM

 

[dorke]

Like @duke37 said it is because the older Analog meters have the internal battery positive feeding the (-)black lead.
Newer Analog Meters(and AVOs) and Digital ones have it connected the conventional way positive to (+)RED.
So for analog meters you never know before you actually test the polarity or look at the schematics of the meter.

 

[HellasTechn]

That makes sense.
Thanks for the info

Have you noticed that With an analogue Multimeter you can more reliably test components like transistor's specially darlington and Fet's ?