Electrical Properties of Soils at ISM Radio Frequencies, From 1 to 40 MHz

Soil electrical properties, conductivity and permittivity, vary with moisture content and temperature. The goal of the work was to generate working correlative functions of the electrical properties of soil over practical ISM radio fJequencies (6.78 to 40.68 MHz) from the Kirtland Air Force Base RF soil remediation project, and its constituent soil types, to facilitate numerical model studies. Correlates were developed to facilitate numerical model temperature and moisture dependence of the electrical properties. Measurements were made in continuous spectra from 1 to 40 MHz for varying moisture content and temperatures of sand, kaolinite, Austin landfill clay, sandy loam and Kirtland Air Force Base soil samples. The measurements were conducted in a 1 5/8" coaxial sample holder with flush mounted center conductor. Impedance data were collected with a Hewlett-Packard 4194A Impedance Analyzer from which calculations of permittivity were made. In general, the relative permittivity and effective loss factor are sensitive functions of water content and temperature.