Patent ID: 6367968
Filing Date: 2002-04-09
Classification: G01B,G01N

Abstract:
A method for determining a thickness of an object having a surface which can be visualized as an array of pixels, comprising the steps of:a) rapidly heating the surface of an object; b) recording pixel intensity in a sequence of IR images, each image having an assigned sequential frame-number related to time elapsed since heating the object surface in step (a); c) developing temperature-versus-time (T-t) data corresponding to a pixel in the sequence of image frames based on frame-number value; d) transforming the T-t data developed in step (c) into complex frequency-domain data having Real and Imaginary components; and e) determining a thickness value for a point on the object corresponding to a pixel based at least upon the complex frequency domain data and a heat-flux pulse migration characteristic time for the object.