An accurate and versatile vibrating capacitor for surface and adsorption studies

The analysis of the desirable features of a vibrating-capacitor probe for adsorption studies and the disturbing effects which hinder their realisation has led to the construction of a set-up which combines low noise and drift, good reproducibility even after movement of the sample, and a low time constant. It is particularly suited for kinetic measurements in adsorption studies for which it is practical to provide direct differentiation of the output; it can also be used for accurate measurements of absolute contact potential differences.