Electrostatic Voltmeters

Many very high impedance (> 10¹⁰ Ω) voltage measurements cannot be made using conventional type voltmeters because charge transfer into the voltmeter is required, thus causing loading and modification of the source voltage. For example, when measuring voltage distribution on a dielectric surface, any measurement technique that requires charge transfer, no matter how small, will modify or destroy the actual data. In these types of applications an electrostatic voltmeter is required.

An instrument that measures voltage with virtually zero charge transfer is called an electrostatic voltmeter. A primary characteristic of electrostatic voltmeters is that they accurately measure surface potential (voltage) on devices or surfaces, with or without physical contact.

We are known for our novel non-contacting voltmeter designs, first introduced in 1968, to address charge transfer issues associated with the contacting voltmeter designs at the time. With these non-contacting electrostatic voltmeters an electrostatic voltage monitoring probe is placed in close proximity (1 mm to 5 mm) to the surface to be measured. These electrostatic voltmeters function to drive the potential of the probe body to the same potential as the measured unknown. This achieves a high accuracy non-contacting measurement that is insensitive to variations in probe-to-surface distances and prevents arc-over between the probe and measured surface.