Method and use of a device for measuring the local effective permittivity of electrically non-conductive or weakly conductive materials

摘要

Method for measuring the local effective permittivity of an object to be examined which has at least one electrically nonconducting and / or weakly conducting material, wherein the measurement is made inductively and the following steps are carried out: - Generation of an electromagnetic alternating field with a frequency in a frequency range of 1 MHz to 100 MHz by an inductive component (13), wherein the electromagnetic alternating field penetrates at least a part of the examination object (7); - Detecting at least one field strength measured value at least one position within the generated alternating electromagnetic field with at least one inductive measuring sensor (3) and determining a by interaction with the examination object (7) at the position of the measuring sensor (3) caused by the change of the inductive component (13) generated electromagnetic alternating field on the basis of the detected field strength measured value in one step, wherein an amplification of the examination object caused by the change of the alternating electromagnetic field by differentially connecting at least two inductive components takes place; - Determining the local effective permittivity for a by the dimensions and position of the measuring sensor (3) with respect to the surface of the examination object (7) fixed partial volume of the examination object (7) from the change of the electromagnetic component generated by the inductive component (13) alternating electromagnetic field; - Assigning the local effective permittivity to the corresponding partial volume of the examination object (7) for each position at which a field strength measured value has been detected.