A planar applicator for masuring surface dielectric constant of materials

An applicator is described which allows the surface dielectric constant of a body to be measured simply by putting the device upon the body itself and by measuring the resulting capacitance value using a hand-held portable capacitance meter. The performances of the sensor were first verified by testing materials with known dielectric properties. Its particular use in measuring the dielectric constant of ceramic materials, plastic materials and of commonly used marbles and stones was then considered. Such application may be of interest in the case where the surface dielectric constant of marble and stone can be related to alterations of the external layer of these materials caused by atmospheric pollutants.