A method is described for testing the coating of metal-coated wire with the aid of the eddy-current method, by passing the wire to be tested through a coil arrangement and exposing it to a high-frequency alternating magnetic field which generates eddy currents in the test object, the inductive feedback of which eddy currents to the coil arrangement is evaluated with regard to amplitude, the frequency of the alternating magnetic field being selected such that the penetration depth of the eddy current into the wire is essentially limited to the thickness of the coating. By selection of the frequency of the alternating field, which is in the range of 0.1-10 MHz and is chosen towards the higher values with decreasing thickness of the coating, testing only of the coating of a metal-coated wire is achieved, without the actual wire core being involved in the testing. In addition to the amplitude evaluation of the inductive feedback of the eddy currents to the coil arrangement, a phase evaluation of this inductive feedback can be carried out, in order to determine the depth of established damage. With increasing depth of the damage, the phase angle of the eddy currents shift in comparison with the phase of the applied alternating field.
