Dielectric relaxation measurements in the ultralow frequency region

摘要

Refinements in the dc transient current method are described for precision measurements of dielectric permittivity from 50 mHz down to 1 μHz. Relaxation increment, relaxation time, and distribution of the relaxation times for a test sample of poly(vinyl acetate) have been measured with satisfactory accuracy as judged by comparison with results from steady‐state measurements. Convenient procedures for numerical Fourier transformation of the observed current are described to easily obtain the complex permittivity.