Nukem Limited

Mannesmann Aktiengesellschaft

Karl Laudenbach

Gerhard Huschelrath

Heinz Schneider

Wolfgang Bottger

Klaus Abend

An instrument for testing of test pieces made of paramagnetic or diamagnetic material as well as of ferromagnetic materials above their Curie point for material defects and/or dimensional accuracy, especially for testing of tubes and slabs above 1000.degree. C. The instrument comprises an electromagnetic transducer (EMT) having magnetic pole shoes and eddy current exciting and receiving windings; and an electronic signal processing unit. The inner pole shoe is conically tapered and fabricated from individual sheets parallel to one another and insulated from each other to prevent the formation of eddy currents that would give rise to undesirable ultrasonic waves that might interfere with the testing process. The pole shoes are positioned so as to develop a magnetic field parallel to the test piece, and the eddy current exciting and receiving windings are heat-insulated with respect to the test piece.

Instrument for testing materials

An electrodynamic ultrasonic transformer, having at least one exciting coil and one receiving coil, for use in ultrasonic nondestructive material testing in order to reduce the dead times and to remove or, respectively, minimize negative influences occurring during the measuring of different test piece material and at distance variations without adversely affecting the signal/noise ratio. Those parts of the exciting coil and/or receiving coil designed for current conducting are preferably made of resistance material which is suitable for structural elements embodying electric resistors, and which material will not essentially obstruct the current flow during the exciting phase of the current, and after termination of the excitation will rapidly reduce the energy stored in stray and coupling fields.

Growing community of inventors

Giessen, Germany

Karl Laudenbach