Dielectric Properties of Some Granular Solids Containing Water

AbstractMeasurements of the complex dielectric permittivity for four granular solids with different water-bonding forces have been performed. Sand, powdered mashed potato powder, and silica gel were tested at a frequency of 9.4 GHz and the modified very-long-sample method was employed. The existence of two ranges of water bonding was confirmed. In the first range, which is below the critical moisture content point, the water appears to have low permittivity because of large adsorption forces, and in the second range free water with high permittivity prevails.