Nondestructive materials testing method and testing device for performing the method

摘要

The invention relates to a method for the nondestructive testing of electrically conducting materials using an inductance measuring bridge (1) provided with at least two test coils (2P and 3P). For the purpose of absolute measurement, the change in the electrical loading of the inductance measuring bridge (1) is determined. At the same time the difference measurement is carried out, the change in impedance between the two test coils (2P and 3P) in the inductance measuring bridge (1) being determined. The testing device according to the invention has an inductive supply (4) for the inductance measuring bridge. The change in the electric loading of the inductance measuring bridge (1) is determined with the aid of a measuring circuit (9M, 18, 19) which is inductively or electrically connected to the inductance measuring bridge (1). To measure the change in impedance between the testing coils (2P and 3P), the diagonal branch (zero branch) (6D, 7D) of the inductance measuring bridge (1) is connected to a first voltage amplifier (8). IMAGE