Patent ID: 7538561

Claim:
A method of detecting an interface between first and second materials having different dielectric loss factors disposed in a stratified manner in a volume of materials using a sensing apparatus having a length of coaxial transmission line including an inner conductor surrounded by a dielectric material and a shielding conductor, a predetermined number of sublengths of the inner conductor being exposed along the length of the transmission line, adjacent sublengths of the exposed inner conductor being separated by shielded sublengths, the method comprising the steps of: exciting the sensing apparatus by a radio frequency signal at a predetermined amplitude, inserting the excited sensing apparatus into the volume of materials to a predetermined depth through the first layer and into the second layer such that a predetermined number of exposed sublengths is disposed within the volume of materials, detecting the signal transmitted through the sensing apparatus and measuring the attenuation of the signal, identifying the interface between strata within the volume based upon the attenuation of the radio frequency signal, wherein the attenuation of the radio frequency signal is proportional to the total number of sublengths of the inner conductor exposed to each of the materials.