Surface and Thin Volumetric Inspections with EMAT

摘要

Guided waves are widely used in non-destructive testing to cover long distances from one source point and to inspect hard-to-reach or inaccessible areas. Using reflection and attenuation methods, ultrasonic guided waves permit locating tight cracks, defects under coatings, and near surface defects that are undetectable with other NDT methods. While Conventional Ultrasonic Testing (UT) techniques require liquid or pressure coupling, Electro Magnetic Acoustic Transducer (EMAT) is a non-contact UT technique that generates ultrasonic waves on metallic materials using electromagnetic induction, thus circumventing the need to use liquid couplant. EMAT systems can be integrated in-line to inspect materials at extreme temperatures and fast production speeds.