EMAT Probe and Technique for Weld Inspection

摘要

A method and apparatus of inspecting for flaws in a specular reflector, wherethe flaws having an expected length and the reflector is electricallyconductive. Themethod comprises directing a beam of an electromagnetic acoustic transmittingtransducer along a beam axis toward the specular reflector for producing areflectedelectromagnetic acoustic beam. The transmitted beam has side lobes with zeropoints therebetween, at least some of the side lobes being major side lobes.Thereflected beam is received using an electro-magnetic acoustic receivingtransmitterset at an angle to the beam axis, the angle being selected to be at one of thezeropoints and passed all of the major lobes of the transmitted beam to eliminaterootand crown signals of the weld, in the reflected signal.