公开(公告)号：US20250044077A1

公开(公告)日：2025-02-06

申请号：US18715434

申请日：2022-12-07

Applicant: ArcelorMittal

Inventor： Nathalie LABBE ,  Shu Hui HAM ,  Gwenaël LE NOC ,  Pauline LEVERONE ,  Jean-Pierre LEBACQ

IPC: G01B11/06

Abstract: A method for estimating the thickness of a varnish coating, having a thickness from 0.5 to 5 μm, of a moving steel substrate including a varnish coating including the steps of i. lighting said moving coated steel substrate with an illumination source forming an incident angle from 51° to 61° with respect to the normal of said steel substrate, ii. p-polarizing the light after reflection on said moving steel substrate and measuring the intensities of the light after reflection on said moving steel substrate, iii. assessing an absorbance spectrum of said varnish coating in said wavelength range iv. assessing an area under the curve of said absorbance spectrum AMEAS v. estimating the varnish thickness using said area under the curve and a function linking a varnish thickness and an area under the curve of an absorbance spectrum of said coating.