Use of TDR Probes to Measure Water Content in Pumiceous Soils

Abstract

The relationship between volumetric water content and the dielectric constant, as proposed by Topp et al. (1980), is widely used in soil science applications. However, there are several well-known exceptions of soils that do not follow Topp's equation, such as organic soils and those of volcanic origin. Such deviations have been attributed to the low bulk density, large surface area or high organic matter. In this paper the dielectric behaviour of some pyroclastic soils from Campania (Italy) is measured against the volumetric water content determined on undisturbed soil specimens. Different volumetric water contents are related to the dielectric constant in order to select the best fitting equation for the examined soils. ? 2012 IEEE.