Ultrasonic transducer with time variable magnetisation - has laminated yoke core generating magnetic field lines parallel to test specimen surface

摘要

The ultrasonic transducer is used generating ultrasonic waves electrodynamically or magnetostrictively use most mostly static premagnetising of horizontal or vertical direction relative to the specimen surface. For the electromagnetic ultrasonic wave generation for material testing purposes is used a magnetic yoke and an ultrasonic transducer. The yoke has a laminated core and the generated magnetic field is time adjustable. The magnetic yoke is of such an arrangement that the magnetic field lines extend parallel to the testing specimen surface. The transmission and receiving of the ultrasonic waves is synchronised with the timing of the magnetic field. For generation of longitudinal waves by electrodynamic method and for generation of transverse waves by magnetostriction the wires of the ultrasonic transducer are arranged horizontal to the surface and perpendicular to the magnetic field lines.