Vermiculite dielectric constant measurement using a volumetric water content probe

This paper aims to present a method to determine the relative permittivity of vermiculite using a volumetric water content probe. The volumetric water content is important in soil characterization, especially for the determination of water absorption curves. The basic principle of the probe used in this study is the measurement of the refractive index of the soil √ε at 100 MHz to allow the determination of the water content through a known relation between these quantities. In this work, a Profile Probe type PR2 (Delta-T Devices, Cambridge, England) was used. Values of 0.98 and 0.99 for the correlation coefficients were obtained in the experiments showing an accurate relationship between the water content and the dielectric constant of vermiculite. A statistical analysis of the data was also made after the realization of the experiments.