Layered-Capacitor Method for Dielectric Bridge Measurements. Algorithms for Inversion and Parameter Fitting. Documentation, Verification, Data Analysis

摘要

Electrical properties of ice are of interest in the analysis of cloud processes (especially of those related to the build-up of electric fields in thunderstorms) and of polar ice soundings. To quantify electrical ice properties and to assess possible effects of atmospheric trace contaminants, the authors measure capacitance and conductance in function of frequency, temperature, and trace solute content. In the frequency range of interest (0.01 Hz to 100 kHz) electrode effects mask intrinsic ice properties. These problems, common to conductive dielectrics, are avoided in the layered-capacitor method by inserting thin layers of a perfect insulator between electrodes and sample. Instrumental improvements have increased bridge measurement accuracy and frequency range. New algorithms are based on a generalized physical model. The methodology developed herein provides a basis for systematic investigation of contaminant effects on the electrical properties of ice and of other conductive dielectrics. Future directions are suggested.