Volume 30, Issue 4 (July 2007)
A Short-circuit Electromagnetic Sensor for Measurement of Soil Complex Permittivity
An electromagnetic sensor is developed for characterization and detection of contamination in geomaterials. The sensor can be used to detect changes in physical and chemical properties of soil and groundwater based on changes in the complex permittivity. The major advantage of the sensor design is the adaptation of short-circuit coaxial line configuration, which makes it readily employed for in situ implementation. A close-form algorithm is developed to convert the measured electromagnetic reflection coefficients S11* by the short-circuit sensor to the complex permittivity of the testing materials. This paper presents a description of the sensor as well as its algorithm developments and the results of complex permittivity measurement. The study indicates that the short-circuit sensor produces reliable measurement of complex permittivity of soil-water systems and can be further developed for in situ contamination detection of soil and groundwater.