Using Impedance Spectroscopy to Characterize the Moisture in Porous Media.

Electrical impedance spectroscopy was used to study the behavior of water in sandy soils. In these studies, impedance and its phase angle were measured between 100 Hz and 100 MHz. The data were transformed into Cole-Cole plots which reveal several relaxation mechanisms over this frequency range. In addition, loss tangent graphs indicate that there is more dispersion with frequency in moist sand samples than in free water indicating that the water is bound differently in the sand than in bulk water. Finally, the graph of relaxation time versus dielectric constant indicates how tightly the water is being held for each mechanism.