Electromagnetic transducer

摘要

The invention relates to an electromagnetic transducer for exciting and receiving ultrasonic waves in testing electrically conductive material without the use of coupling means, chiefly in the testing of workpieces made from steel. Whereas to date printed conductors have been arranged on flat printed circuitboards and could be connected there to form coils, the invention provides magnetising windings in association with pin-shaped RF cores. The latter form the base elements of a multiple arrangement in which they must exhibit specific spacings prescribed in accordance with the invention. They can then be operated as singular point or line emitters or in a linear or planar array, and as planar emitters, and facilitate an improved signal-to-noise ratio in ultrasonic testing, specifically in particular with the use of very high transmitter frequencies. The crosstalk sensitivity is reduced in this case in such a way that the error detection is substantially improved.