DEVICE FOR INSPECTING A MOVING METAL STRIP

摘要

A device for inspecting a moving metal strip includes a first electromagnetic acoustic transducer having an ultrasonic wave emitter. The waves emitted from the emitter are emitted to be incident on a first edge of a surface of the strip, and the emitter is not in contact with the strip. A second electromagnetic acoustic transducer is provided and includes an ultrasonic wave receiver. The waves received emerging from an area of the strip surface toward the receiver, the receiver is not in contact with the strip. A processing unit is coupled to the second electromagnetic acoustic transducer to provide an inspection criterion using a signature of the ultrasonic waves measured. The area is located on the strip such that a wave path between the first edge of the strip and the area is aligned in a linear direction mainly transverse to the direction of movement of the strip.