MEASUREMENT OF MOISTURE-CONTENT WITH A PENETROMETER

Interpretation and reliability of in situ tests, such as cone penetrat ion, can be improved if in situ moisture content and density can be me asured without affecting the speed of site investigation significantly . This paper describes the principle and technique of determining mois ture content with a penetrometer that can measure the dielectric const ant (specific inductive capacitance) of soils. Effects of various fact ors, such as salt content of water, on the measured parameter are disc ussed with special reference to frequency of the measuring bridge. Thi s study shows that it is possible to determine the in situ moisture co ntent of soils from measurements conducted at very high frequencies. T his method presents particular promise because the moisture content ve rsus capacitance relationship has been found to be practically indepen dent of soil type.