Patent ID: 9217728
Filing Date: 2015-12-22
Classification: G01N

Abstract:
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.