Abstract: The method according to the invention comprises producing an alternating magnetic flux coupled to an electrically closed loop which includes a pipeline to be checked, and measuring at least on electromagnetic field parameter over the whole length and perimeter of the pipeline. The distribution function of the electromagnetic field parameter thus obtained is indicative of the state of the pipeline. The method is more effective than the conventional techniques in that it ensures a more uniform spreading of current over the pipeline, in that it makes possible to inspect hard-to-get-at portions of pipelines without installing magnetic flux excitation means at those portions, and in that it rules out the effects of the magnetic flux on the output signals of measuring transducers. The invention is further concerned with a device for nondestructive inspection of pipelines primarily, pipelines, of atomic power stations.

Abstract: The proposed eddy current converter for non-destructive testing of electrically conductive coating in holes of printed circuit boards comprises a cylindrical frame enveloped by an exciting winding and a measuring winding and inserted into a hole of a printed circuit board being tested. The coils of the exciting and measuring windings extend along the generatrices of the cylindrical frame.With the use of the proposed converter, the testing accuracy is independent of the parameters of respective contact areas of a hole being tested. The converter of the present invention is sensitive to the most undesired flaws like transversely extending cracks.