Measurement of the Electrical Conductivity and Dielectric Constant without Contacting Electrodes

Abstract

A method is developed whereby electrical conductivity and dielectric constant of semiconducting and dielectric materials without contacting electrodes can be measured. The principle of this method is that a specimen suspended in a rotating field with a fine fiber is rotated by the torque proportional to the electrical conductivity or the imaginary part of its complex dielectric constant, and the torque exerted on it by a linearly polarized field is proportional to the real part of its dielectric constant. An analysis of the method and some preliminary measurements of conductivity, photoconductivity, the dielectric constant of cadmium sulphate crystals and the dielectric loss of the lamella containing CdS powder are presented. The latter shows the photodielectric effect.