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.

主权项

1. A device for inspecting a moving metal strip, the device comprising:
a first electromagnetic acoustic transducer (EMAT) having an ultrasonic wave emitter, said first EMAT being disposed above a first lateral edge of the metal strip, ultrasonic waves being emitted from said ultrasonic wave emitter being incident on a first edge of a surface of the metal strip, said ultrasonic wave emitter not being in contact with the metal strip; a second EMAT having an ultrasonic wave receiver receiving ultrasonic waves originating from said ultrasonic wave emitter of said first EMAT, said second EMAT being disposed at a second lateral edge of the metal strip opposite the first lateral edge, the ultrasonic waves being received emerging from an area of a strip surface disposed toward said ultrasonic wave receiver, said ultrasonic wave receiver not being in contact with the metal strip; a processing unit coupled to said second EMAT and providing at least one inspection criterion using at least one signature of the ultrasonic waves measured at said second EMAT; and the area of the strip surface disposed on the metal strip such that a wave path between the first edge of the metal strip and the area is aligned in a linear direction mainly transverse to a direction of a movement of the strip.