Patent ID: 6561035
Filing Date: 2003-05-13
Classification: G01N

Abstract:
An apparatus for nondestructive testing of metallic structures comprising:(A) a housing having a circular opening surrounding an exterior circumferential wall of a substantially cylindrical metallic object; said substantially cylindrical metallic object translatable, along its longitudinal axis, through the housing; and (B) a first electromagnetic acoustic transducer comprising: (1) a first plurality of substantially similar permanent magnets mounted in the housing and arranged in a first array and positioned substantially in planar radial fashion, about a first radial center, around the circular opening at substantially equal intervals with ends of adjacent magnets possessing opposite polarity; said first array positioned transverse to, and with the first radial center substantially colinear with, the longitudinal axis of said substantially cylindrical metallic object; each of said first plurality of substantially similar permanent magnets comprising: (a) a first end adjacent to the circular opening and (b) a second end substantially perpendicular to and spaced from the circumferential wall wherein the second end is notched in the plane substantially colinear with the longitudinal axis of the substantially cylindrical metallic object; and (2) a first electrically conductive wire coil mounted in the housing and positioned within an annular channel formed by the notched second ends of the first plurality of substantially similar permanent magnets.