Method and device for the spectral analysis of a metal coating layer deposited on the surface of a steel strip

摘要

The present invention relates to a method for the spectral analysis of a metal coating layer deposited on the surface of a steel strip (1), characterised by the following steps: said strip is moved along an arc of the outer surface (813) of a rotating roller (8) with a cylindrical wall guiding the strip by contact; a so-called ablation laser beam is guided into an internal cavity of the cylindrical wall in order to be placed in optical incidence under a normal axis (41) on the outer surface of the roller on a targeted contact point (11) of the strip and the roller, said beam passing through the wall via a wall opening (811), which is transparent to the beam; a plasma spectral emission distribution from the laser ablation to the contact point is collected by optical feedback in the direction of the normal axis (41) on the outer surface of the roller and through the opening in order to be guided towards a spectral measurement unit; and the normal axis on the outer surface for the optical incidence and feedback is placed in synchronous rotation with the roller. The invention also relates to a device with a plurality of embodiments for implementing the method of the invention, as well as to the advantageous uses thereof.