Method for measuring the local effective permittivity of electrically non-conductive or weakly conductive materials

摘要

The invention relates to a method for measuring the local effective permittivity of examination objects (7), which have at least one electrically nonconductive and / or weakly conductive material. By means of one or more inductive components (13), a high-frequency alternating electromagnetic field is generated in a frequency range of preferably 1 MHz to 100 MHz, the change, caused by the examination object (7), by means of inductive, possibly differentially interconnected sensors (3) is measured , The measurements can be carried out without contact or with sliding contact with the examination subject (7), it being sufficient to have access to the examination subject (7) from one side. In addition, the testing of complex components is possible. Advantage of the method is the possibility of characterization of conductive and non-conductive examination objects (7), since the frequencies used are below the microwave range. With a measuring device (1) operating according to this method, local statements or homogeneity maps (by scanning measurements) with respect to dielectric material properties, material composition, material condition and / or geometric properties can be derived.