<title>True color tube bore inspection system</title>

Abstract

A True Color Tube Bore Inspection System (TCTBIS) has been developed to aid in the visual nondestructive examination of the inside surfaces of small bore stainless steel tubes. The instrument was developed to inspect for the presence of contaminants and oxidation on the inner surfaces of these 1 .5 to 1 .7 millimeter inside diameter tubes. Previously a parameter called the color factor, which can be calculated from the images collected by the TCTBIS, was found to be a good measure of the surface quality in these tubes. The color factor is a global number in the sense that itis calculated for the entire inspection region. Additional algorithms have also been developed to evaluate the tube based on surface inhomogeneities that are indicative of the presence of foreign matter, local chemical attack or other undesirable but localized conditions. These algorithms have been incorporated into an up-to-date apparatus which is described in detail. We have also investigated the feasibility of using artificial intelligence techniques to aid in the interpretation of these defects. Promising results were obtained with a feed forward, back propagation artificial neural network.