Volume 25, Issue 2 (June 2002)
Improved Complex Permittivity Measurement and Data Processing Technique for Soil-Water Systems
The complex permittivity of soil-water systems is a function of a number of soil properties. By measuring the complex permittivity, one could quantitatively evaluate the soil behavior under existing conditions in the field, as well as identify changes in the environment. This paper describes the improvement of a measurement and data processing technique for the analysis of the complex permittivity of soil. A sample holder described in a previously published study is modified to reduce errors from sample handling and to increase the measurement accuracy and capacity. A modular unit is designed to measure the static conductivity and the complex permittivity of the soil simultaneously. The data processing technique is also presented, including the identification of the frequency for data analysis and extraction of the static conductivity from the measured loss factors. The results of the complex permittivity measurements on a compacted natural clayey till are presented to demonstrate the typical relationships of the soil complex permittivity as they are related to the soil volumetric water content, bulk density, and salinity.