A Dielectric Spectrometer for Liquid Using the Electromagnetic Induction Method

Abstract

Dielectric spectroscopy is useful for the characterization of colloidal dispersions. In the past, dielectric spectroscopy has been attempted using parallel metal electrodes to measure the permittivity and conductivity of colloids. However, it is difficult in practice to make these measurements in conductive solutions because large measurement errors can be caused by electrode polarization, which is a kind of contact impedance between the electrode and the solution. Electrode polarization behaves like a capacitance and masks the true properties of the solution at low frequencies. The HP E5050A colloid dielectric probe was developed for colloidal liquid evaluation. Its electromagnetic induction technique eliminates the electrode polarization effect. The probe operates from 75 kHz to 30 MHz with the HP 4285A precision LCR meter and HP VEE software on an HP Vectra or compatible computer (Fig. 1). The HP VEE environment 1 provides easy operation, display, and analysis of the measurement data.