A ferromagnetic strip sensor for use in magnetostrictive testing of various structures. In its simplest form, the sensor has a ferromagnetic strip with an electrical coil winding. A permanent magnet is positioned atop the strip, aligned with but offset from, a center axis of the strip. The sensor is operable such that a time varying current in the coil results in a unidirectional guided wave. This guided wave travels within the structure, and is reflected from anomalies in the structure.
Sergey A. Vinogradov; Glenn M. Light; Charles E. Duffer