An Electrode Setup for Non-contact Dielectric Response Measurement

Abstract

The dielectric response measurement is a widely used technique for characterizing dielectric materials. However, the contact problems between samples and electrodes existing in the use of conventional electrode setup limit the accuracy of the measurement. This paper studies an electrode arrangement that avoids direct contacts of the sample with the electrodes on both sides. The edge effect of this arrangement is calculated by the FEM model. The equations to derive the complex permittivity are presented. The measurement instrument is described and the influence of the small voltage between its measure and guard terminals is analyzed. The error sensitivities of the non-contact and contact methods are compared. The results show that this electrode arrangement can be used to perform non-contact measurements, the edge effect of it is not significant, and the guard voltage is not an obstacle to obtain results with high accuracy. Overall, the non-contact electrode arrangement combined with the IDAX 300 can potentially improve the accuracy of dielectric response measurements although the non-contact methods can increase the sensitivities to errors.