Measurement of Frequency-Dependent Conductivity and Relative Permittivity of a Soil Using Two Parallel Electrodes

Abstract

Impedance of cylindrical specimens of a soil having three different lengths is measured at frequencies ranging from 40Hz to 40MHz using two parallel electrodes in order to estimate and remove the effect of the contact impedance. Both conductivity and relative permittivity of the tested soil increase with increasing the moisture ratio. The conductivity of the soil having a moisture ratio of 5% is almost constant (about 3mS/m) at frequencies lower than 10MHz, and increases with increasing frequency beyond 10MHz. The relative permittivity of the same soil decreases with increasing frequency up to 10MHz, at which it is 7.