DEVICE FOR TESTING FERROMAGNETIC MATERIALS

摘要

Device for testing ferromagnetic materials, such as pipelines and the lik e, for faults, cracks, corrosion, etc., with at least one electromagnetic ultrasonic transducer with at least one high frequency current coil in connection with a magnetic field for exciting and/or detecting ultrasonic waves in the material wall and at least one magnet system producing the magnetic field, characterized in that the ultrasonic transducer is located between the pole pieces of different polarity of an additional magnet arrangement producing a magnetic prefield in the material wall.