Wednesday, 12 October 2016
Where F is a body force per unit volume, J is the induced dynamic current density, and B is the static magnetic induction. The most important application of EMATs has been in nondestructive evaluation (NDE)applications such as flaw detection or material property characterization. Couplant free transduction allows operation without contact at elevated temperatures and in remote locations. The coil and magnet structure can also be designed to excite complex wave patterns and polarizations that would be difficult to realize with fluid coupled piezoelectric probes. In the inference of material properties from precise velocity or attenuation measurements, use of EMATs can eliminate errors associated with couplant variation, particularly in contact measurements.