Workpiece e.g. band material, coating layer thickness monitoring method, involves directing laser bursts towards coating, and detecting change in layer thickness of coating, by change of ratio compared to reference value

摘要

The method involves directing laser burst towards a coating so as to produce plasma at the surface of the coating. A crater is produced in the coating, by adjusting the laser parameters. The depth profile of the chemical composition of the coating is determined, by evaluating the optical emission of the plasma. The change in layer thickens of the coating is detected, by a change of a ratio compared to a reference value.