초록 ▼

In an infrared (IR) transient thermography system a sequence of image frames is acquired from an IR sensitive focal-plane array camera. Each sequentially acquired image frame is made up of an array of pixels and has assigned a frame-number that corresponds to elapsed time. Temperature-versus-time (T

In an infrared (IR) transient thermography system a sequence of image frames is acquired from an IR sensitive focal-plane array camera. Each sequentially acquired image frame is made up of an array of pixels and has assigned a frame-number that corresponds to elapsed time. Temperature-versus-time (T-t) data corresponding to each pixel is developed from stacks of sequential image-frames. A method of analyzing the stacks of thermal data image-frames is presented wherein either the Real or the Imaginary component portions of a Fast-Fourier Transform of a normalized T-t data curve from each pixel is used to determine the thickness of an object and produce a color-keyed or gray-scale coded thickness map.

대표청구항 ▼

1. 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 rel

1. 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.