X-RAY REAL-TIME EVALUATION OF A NEW LINE DETECTOR FOR INSPECTION OF STRIPPED STEEL

The development of radiographic methods in the steel industry has been restricted by the necessary use of photographic film as a sensor. The available real time radiographic devices do not provide sufficient image resolution for the user's requirments. However, X-ray solid-state linear sensors offer new promising possibilities for radiographic image acquisition of moving products. The resolution performance of such devices have been compared with those of a conventional radiographic film obtained under optimal conditions. Of course, it was not possible to compare these systems in a general manner, on all types of products. We restricted ourselves to the conditions involving the detection of inclusions clusters in hot and cold-stripped steel up to 3 mm thick. It showed that these devices gave very interesting results, without attaining the sharpness of radiographic film. X-ray solid-state linear detectors are very well suited to the detection of long defects on moving products. In this case, special algorithms were developed in order to improve the sharpness of the image and the automatic detection of defects. They show the feasibility of a real time application with architecture built around the VME bus and specialized video rate image processing boards.