Patent ID: 6346704
Filing Date: 2002-02-12
Classification: B27N,G01N

Abstract:
A process for the detection of flaws in an article using Far infra-red scanning of its surface comprising changing the temperature of the surface of an article over a plurality of temperatures and making an infra-red scan at each of said temperatures during changing the temperature, the infra-red scans being separated one from another by equal time increments;characterized in the steps of allocating parts of said surface as central and marginal parts, forming images from said infra-red scans, digitizing said infra-red scans, digitizing the images to provide a sequence of digitized scanned images; for said central part of the surface, comparing data directly from said digitized scanned images and noting variations and/or anisotropies from a general cooling pattern for the article and deducing the presence of flaws at locations in the article corresponding to the location of the variations and/or anisotropies in the comparison of the digitized scanned images; and for the marginal part of the surface, performing thermodynamic modelling on one of the digitized scanned images to provide an estimate of the temperature distribution for a hypothetic unflawed article after passage of one of said time increments, and comparing data from an adjacent digitized scanned image with said estimate and noting variations and/or anistropies of the structure of the marginal part of the article.