Development and applications of fringing electric field dielectrometry sensors and parameter estimation algorithms

Recent advances in the field of interdigital w - k (frequency-wavenumber) d ielectrometry are described. The paper offers an overview of several applic ations of this technology developed during the last few years. Interdigital w-k dielectrometry offers the ability to non-destructively measure from on e side dielectric permittivity, conductivity and related physical propertie s distributed spatially throughout the volume of dielectric materials. A se parate mapping may be required to translate the distribution of the complex dielectric permittivity into the distribution of other properties, which i nclude moisture concentration, impurity concentration, density, porosity, t hickness of films, structural integrity, surface coatings, etc. As represen tative examples of applications of this technology, the results of the meas urement of moisture diffusion into a 1.5 mm thick oil-free transformer pres sboard are presented, followed by an illustrative case of spectroscopy-base d landmine detection.