Measuring voltage with oscilloscope.

Lets say I have a serial circuit of - Vsource, 2 resistors, and GND - like this:

GND ------- -Vsource+ ------------- R1 ---------- R2 --------- GND

If I'd measure the voltage on R1, and put the probe's GND and probe's other end around R1, wouldn't it be a problem that I created two different grounds in the circuit?

alphacat said:

Lets say I have a serial circuit of - Vsource, 2 resistors, and GND - like this:

GND ------- -Vsource+ ------------- R1 ---------- R2 --------- GND

If I'd measure the voltage on R1, and put the probe's GND and probe's other end around R1, wouldn't it be a problem that I created two different grounds in the circuit?

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hi,
Its that ambiguous word 'ground' which causes problems.

Just for example: say your power supply and scope chassis were not connected to the mains Earth/Ground line.

You could take a reading across R1 OK.

But if the psu and scope chassis are connected to the Earth/Ground line, which IMO they should always be, then you cannot measure across R1.

I would suggest you use the term 'common' or '0V' for connections on your circuits and keep the 'ground' to refer to 'Earth'.