DC voltage measurement

When you want to measure DC voltage, you have a choice of methods which are more or less suited to the task in hand.

We can classify measurement methods or equipment into three broad categories.

• Opposition or zero methods: measurements are made by comparison with precise reference voltages. With this type of method, relatively low uncertainties can be achieved (10 ^–5 to 10 ^–7 ).

• Methods using analog voltmeters: these devices convert voltage into mechanical displacement. They cannot achieve uncertainties of less than a few 10 ^–3 .

• Methods using digital voltmeters: the measurement is displayed directly in numerical form; most of the time, the change of gauge is automatic, as is the indication of polarity.