Electrostatic fieldmeter

This force is converted to volts, measuring both the initial peak voltage and the rate at which it falls away.

a charge monitoring probe is placed close (1 mm to 5 mm) to the surface to be measured and the probe body is driven to the same potential as the measured unknown by an electronic circuit.

This achieves a high accuracy measurement that is virtually insensitive to variations in probe-to-surface distances.

The operation of an electrostatic field meter is based on the charge-discharge process of an electrically floating electrode: Corona source charges a floating electrode, which discharges with a regular repetition frequency to the earth-electrode.

The discharge repetition frequency is the measured variable which is a function of the background electrostatic field.