Ultrasonic inspection of a cylindrical object

摘要

A method and an apparatus are provided for ultrasonically inspecting a cylindrical object. The object is placed between the poles of a magnet to create a circumferential magnetic field in the object. A group of electromagnetic transducers (EMAT's) are placed adjacent the material so that the transducers scan the entire object when it is rotated. When an RF signal is applied to the transducers, elastic waves are generated in the material. These elastic waves reflect from defects in the material and these reflections are received by the transducers.