Abstract: The present invention relates to a method for detecting temporally varying thermomechanical stresses and/or stress gradients over the wall thickness of metal bodies, in particular pipelines. In the method, the temperature on the outer surface of the body is measured in order to determine a temperature progression and stress progression therefrom. In addition, electromagnetic ultrasonic transducers are used at at least one measuring point on the outer surface in order to determine the progression of the stresses and/or stress gradients over time over the wall thickness of the body in conjunction with the result of the temperature measurement. The method allows the fatigue monitoring of pipelines even in the event of rapid stress changes.

Abstract: The present invention relates to a method for detecting temporally varying thermomechanical stresses and/or stress gradients over the wall thickness of metal bodies, in particular pipelines. In the method, the temperature on the outer surface of the body is measured in order to determine a temperature progression and stress progression therefrom. In addition, electromagnetic ultrasonic transducers are used at at least one measuring point on the outer surface in order to determine the progression of the stresses and/or stress gradients over time over the wall thickness of the body in conjunction with the result of the temperature measurement. The method allows the fatigue monitoring of pipelines even in the event of rapid stress changes.

Abstract: A method is described for non-destructive material testing on a workpiece comprising an electrically conductive material using EMUS transducers, each of which has a magnet unit for locally introducing a magnetic field into the workpiece, and also has a radio frequency (RF) coil arrangement, which interacts with the magnetic field. The invention is distinguished in that at least two transcuers are spaced apart along a surface of the workpiece. At least a first EMUS transducer generates and also measures ultrasound waves within the workpiece and the second EMUS transducer functions as a reception transducer for at least detecting ultrasound waves.

Abstract: An electromagnetic ultrasonic transducer for coupling-media-free generation and/or reception of ultrasonic waves in the form of linearly polarized transverse waves in and from a workpiece is disclosed, having at least one unit which converts the ultrasonic waves inside the workpiece and which is provided with a coil for generating, and/or detecting a high-frequency magnetic field and premagnetizing unit for generating a quasi-static magnetic field which superimposes the high-frequency magnetic field in the workpiece The coil is disposed in a torus-shape on at least one partially toroidal or U-shaped magnetic core, having two front ends which can be turned to face the workpiece. The front ends of the magnetic core, which can be turned to face the workpiece, are connected directly or indirectly to a magnetic flux piece which has a surface facing the workpiece and connecting the front ends with each other.

Abstract: Disclosed is an electromagnetic ultrasonic transducer for coupling-media-free generation and/or reception of ultrasonic waves in the form of linearly polarized transverse waves in a, respectively from a workpiece, having at least one unit which converts the ultrasonic waves inside the workpiece and which is provided with a coil arrangement for generating, respectively detecting a high-frequency magnetic field as well as with a premagnetizing unit for generating a quasi-static magnetic field which superimposes upon the high-frequency magnetic field in the workpiece, with the coil arrangement being disposed in a torus-shaped manner on at least one partially toroidal or U-shaped magnetic core, which each has two front ends which can be turned to face the workpiece.

Abstract: The present invention relates to an electromagnetic ultrasonic transducer for generating horizontally polarized transverse waves. The transducer comprises a coil support (4) which is made of a material having good magnetic conductivity and which is provided with a comb-like structure having parallel running channels (5) and fins (6). A plurality of HF coils (1) which are electrically interconnected in series are wound on at least some of said fins 6 at some distance the faces of said fins (6) with adjacent coils (1) having an alternating direction of wind. In the channels (5) are arranged a plurality of rows (3) of permanent magnets (2) having alternating pole assignment. With the present ultrasonic transducer, in particular low-frequency SH waves can be generated in or receiving out of electrically conductive materials without the risk of wearing the HF coils.

Abstract: The present invention relates to an electromagnetic ultrasonic transducer for generating horizontally polarized transverse waves. The transducer comprises a coil support (4) which is made of a material having good magnetic conductivity and which is provided with a comb-like structure having parallel running channels (5) and fins (6). A plurality of HF coils (1) which are electrically interconnected in series are wound on at least some of said fins 6 at some distance the faces of said fins (6) with adjacent coils (1) having an alternating direction of wind. In the channels (5) are arranged a plurality of rows (3) of permanent magnets (2) having alternating pole assignment.

Abstract: Device for testing ferromagnetic materials, such as pipelines and the like, for faults, cracks, corrosion, etc. An one electromagnetic ultrasonic transducer includes at least one high frequency current coil and an arraay of permanent magnets which create a magnetic field for exciting and/or detecting ultrasonic waves in the wall of the ferromagnetic material. The ultrasonic transducer is located between the pole pieces of an additional magnet arrangement that produces a magnetic prefield in the material 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.