Patent ID: 6120833
Filing Date: 2000-09-19
Classification: G01B

Abstract:
A method for continuously measuring, without any contact, the thickness of an insulating coating while the insulating coating is being applied to a moving metal substrate, using measurement means comprising input measurement means and output measurement means each including first and second distance measurement sensors, said method comprising:moving the metal substrate successively into a field of the input measurement means, to means for applying the coating, and then into a field of the output measurement means, the first distance measurement sensor of each of the input and output measurement means being an inductive effect sensor and the second distance measurement sensor of each of the input and output measurement means being configured to measure the distance to the surface of the substrate without any contact;making a first pair of measurements of the distance to a zone of the substrate before applying the coating on the zone of the substrate using respectively the first and second distance measurement sensors of the input measurement means;applying the insulating coating on the zone of the metal substrate;making a second pair of measurements of the distance to the zone after application of the insulating coating to the zone, using respectively the first and second distance measurement sensors of the output measurement means;calculating a first difference between the first pair of measurements;calculating a second difference between the second pair of measurements;determining a thickness of the coating applied to the zone, to within a possible corrective factor from a difference between the first difference and the second difference.