Time domain reflectometry techniques for water content measurement

摘要

Time domain reflectometry (TDR) is becoming a widely used method for measuring water content in porous materials. In this method, the relative dielectric permittivity is first measured, then the water content is deduced from it by means of models or experimentally fitted formulas. Lichtenecker's mixing model, which is applied on moist porous materials, is examined. For testing this model, a large set of materials has been selected and the electric permittivities measured by TDR on the whole range of water saturations. The results obtained show that Lichtenecker's model is suitable for taking into account the effects of bulk density, or porosity, and mineralogical compositions.