One of the specifications for an analogue multimeter or VOA meter is its sensitivity. This comes about because the meter must draw a certain amount of current from the circuit it is measuring in order for the meter to deflect. Accordingly the meter appears as another resistor placed between the points being measured. The way this is specified is in terms of a certain number of Ohms (or more usually kOhms) per volt. The figure enables the effective resistance to be calculated for any given range.

Thus if a VOA multimeter had a sensitivity of 20 kOhms per volt, then on the range having a full scale deflection of 10 volts, it would appear as a resistance of 10 x 20 kohms, i.e. 200 kohms.

When making measurements the resistance of the meter should be at the very least ten times the resistance of the circuit being measured. As a rough guide, this can be taken to be the highest resistor value near where the meter is connected.

Normally the sensitivity of an analogue meter is much less on AC than DC. A meter with a DC sensitivity of 20 kohms per volt on DC might only have a sensitivity of 1 kohm per volt on AC.