The influence of current and potential distribution on the measurement of dielectric permittivity

Abstract The impedance responses of three different electrode geometries in contact with synthetic motor oil were measured and shown to exhibit constant-phase element (CPE) behavior in the geometric impedance. A mathematical model that accounts for frequency dispersion in the geometric impedance was developed and shown to be in agreement with experimental measurements. The electrical properties observed were shown to be influenced by nonuniform modulating electric fields, in agreement with observations reported in the literature. In this work, the influence of electrode geometry and frequency dispersion on impedance spectra was identified and used to develop a method to estimate the electrical properties of non-ideal materials.