Small question about Voltmeter.

Hey,

I wanted to ask please, does a voltmeter know what is the + and what is the - of the DUT by sensing the direction of the current which flows through it when connected in parallel with the DUT?

Thanks.

It simply senses the polarity of the voltage, not the current. It likely senses whether the input is positive or negative with respect to the common lead with a comparator and adjusts the input polarity to the voltmeter circuit so it measures the voltage properly.

Thanks.

Isnt the voltage polarity set by the current flow's direction?

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I mean, i thought that the only way to determine the voltage's polarity was to check the flow direction of the electrons.

alphacat said:

Thanks.

Isnt the voltage polarity set by the current flow's direction?

--
I mean, i thought that the only way to determine the voltage's polarity was to check the flow direction of the electrons.

Click to expand...

On a microscopic level, that's true. However, we think of things like comparators and op-amps as voltage devices. It just makes analysis easier.