Optimizing Voltage Measurement in High Resistance Circuits

[Idea04]

What is the best way to measure the voltage from a high resistance circuit?
The circuit resistance is higher than the resistance of the voltmeter.

 

[Studiot]

You haven't really provided much to go on.

It could be that your voltmeter is not very high impedance so you simply need to get a higher impedance one.

Depending upon the voltage you wish to measure, and the circuit it occurs in, one way is to use a null method. The voltage to be measured is balanced for a null against a known variable voltage or by means of a potentiometer.

Yet another method is to devise a measurement circuit where you switch alternately between a standard voltage and the one to be measured. Your measurement circuit then compares the effects of both voltages.

hope this helps

go well

 

[sophiecentaur]

In the 'olden days' when there just didn't exist high impedance voltmeters, people always used a 'Potentiometer.' (See above). Nowadays, you could use a feedback circuit with a high gain op amp to match the test voltage with another equal voltage from a low impedance source and then measure the value of this voltage.

 

[Proton Soup]

i would connect a low-leakage capacitor to it, then come back tomorrow and read the voltage. ;)