Abstract: A method for electromagnetic ultrasonic conversion includes exerting dynamic-mechanical forces upon particles of an electrically conductive material of a test sample by superimposing quasi-static magnetic and electromagnetic high-frequency fields of a transmission converter for generating ultrasonic vibrations when transmitting. Electrical fields are induced by waves arriving in the test sample resulting in vibrations of the particles of material inductively affecting the fields of a receiver converter when receiving. The excitation of the vibrations when transmitting and the induction of electrical fields when receiving are effected by Lorentz and magnetic forces as well as by magnetostriction forces if the test sample is ferromagnetic. Fill level and bubble formation are monitored in enclosures in the form of containers and pipelines for liquid, by coupling a transmission converter and a receiver converter to an enclosure wall.

Abstract: The invention relates to a method for non-contact, non-destructive testing of a test body of ferromagnetic and/or electrically-conductive material with ultrasound waves, comprising the steps of: producing in a near-surface region of the test body a low-frequency alternating magnetic bias field having flux lines generally parallel to a surface of the test body; producing high frequency alternating magnetic excitation fields in said near-surface region generally parallel to said surface during a time interval when the bias field is at a quasi-static maximum, adjacent excitation fields having opposing polarity and having flux lines lying in mutually parallel directions, whereby ultrasound waves are generated in the test body; and detecting high frequency alternating magnetic fields in said near-surface region during the same time interval when the bias field is at a quasi-static maximum and producing a signal therefrom representative of said ultrasound waves.