Effect of Carbon Dioxide on Relative Dielectric Constant and Conductivity of Pure Water in Frequency Region under 200 kHz

Abstract

In order to use pure water as an alternative to insulating oil, the conductivity of pure water must be at least four orders of magnitude lower. It is important to investigate the frequency characteristics of relative dielectric constant and conductivity of pure water to investigate the charge carriers that determine the conductivity. It is necessary to use metal electrodes to determine the relative dielectric constant and conductivity. However, since electrodes can affect relative dielectric constant and conductivity, true relative dielectric constant and conductivity are not yet clarified. In this paper, we investigated the frequency characteristics of the relative dielectric constant and conductivity of pure water dissolved in carbon dioxide using high purity carbon electrodes. As a result, it was clarified that the conductivity of pure water in which carbon dioxide was dissolved did not change much in low frequency region, but relative dielectric constant showed huge value as the frequency decreased.