Dielectric methods and apparatus for in situ prediction of porosity and specific surface area (i.e., soil type) and for detection of hydrocarbons, hazardous waste materials, and the degree of melting of ice and to predict in situ stress-strain behavior

摘要

A soil probe, comprising, in one form, a cylindrical member of insulating material having a pair of metal, electrically conductive, ring electrodes mounted a short distance above a conical portion at the lower end of the probe, these ring electrodes lie flush with the outer surface of the cylindrical member and are spaced apart from each other by the insulating material. An electrical-electronic measuring system is connected to the electrodes by conductors providing identical line impedance for each ring. The system has an initial electronic portion inside the cylindrical member and close to the electrodes and has a second portion distant from the cylindrical member. A plurality of different frequencies of radio-frequency current is applied to the electrodes, for accurate determination of capacitance at the different frequencies. Therefrom are determined the dielectric dispersion characteristics of the soil. A soil probe with three electrodes in a cylindrical tube can be used to predict the stress-strain behavior in situ and properties such as &lgr;, &kgr;, and M from such measured properties and (A.sup.2 /f), &Dgr;&egr;, and (e.sub.1 /e.sub.t) versus &kgr;.