Measurement of surface potentials

Abstract

The measurement of surface potentials by the vibrating plate method is particularly well suited to the use of a phase-sensitive detector. The authors have built equipment with such a detector as a measuring device. This allowed them to improve the signal-to-noise ratio and thus to increase the sensitivity of the measurement. The tests made on this equipment showed that a sensitivity of 0.01 mV is possible but the instability of the potential to be measured limits this sensitivity to 0.1 mV.