Electrostatic Voltmeters and Instrumentation

Theory of operation – AC feedback electrostatic voltmeter

Trek offers two types of electrostatic voltmeters. One product line utilises DC feedback technology while the other product line is based on Trek’s novel approach to electrostatic measurement via patented AC feedback technology.

The AC feedback electrostatic voltmeters are based on a unique design developed and patented by Trek to address some of the problems associated with electrostatic field meter technology. The AC feedback technology delivers accurate measurements over a wide range of probe-to-surface spacings without the need to generate high voltage. Compare this to field meter technology which requires a specific fixed spacing in order to provide useful measurements. In addition, the AC feedback electrostatic voltmeter can measure smaller surface areas than field meters because Trek’s technology allows the probe to be placed closer to the surface.

Theory of operation – DC feedback electrostatic voltmeter

The DC feedback electrostatic voltmeters use a well-known technology that Trek has employed for over 45 years. The design utilises a field-nulling method where the body of the probe is driven to the voltage being measured. This provides very high accuracy and fast speed of response. Since the probe is spaced relatively close to the surface being measured (1-2mm typical) it is capable of measuring very small surface areas, with no arc over.