DEVICE AND METHOD FOR ELECTROMAGNETIC ACOUSTIC MATERIAL INSPECTION AND/OR MEASURING THICKNESS OF OBJECT UNDER TEST, HAVING ELECTROCONDUCTIVE AND FERROMAGNETIC COMPONENTS Russian patent published in 2010 - IPC G01N29/04 

FIELD: physics.

SUBSTANCE: permanent magnet or electromagnet has a U-shaped body whose magnetic poles lie adjacent by their planes to an engineering surface, or which is similar to a bridge, surrounds the region of the engineering surface, designed for placing eddy current coils on the side of the test object. The permanent magnet creates a tangential magnetic field in the test object directed in parallel to the engineering surface and the eddy current coil has geometry through which a spatially confined region is created within which inside the test object there is a resultant eddy current field with high eddy current density compared to other surrounding spatial regions, as well as with the same direction of the said currents. The direction of eddy currents in the field induced in the test object in the region of high eddy current density is perpendicular to the direction of magnetic field lines of the tangential magnetic field. The eddy current coil is made in form of a three-dimensional frame with a real or virtual core on the real or virtual surface of which an electric conductor is wound with the same winding direction.

EFFECT: considerable reduction or absence of wearing of the eddy current coil when inspecting the sample on its entire thickness, possibility of using an eddy current coil in which eddy current has high density in the same direction so that the phenomenon of impact wave cancellation inside the test object is considerably lowered or absent.

22 cl, 18 dwg