Optical method and device for automatically classifying cylindrical nuclear-fuel pellets

摘要

In order to classify cylindrical nuclear-fuel pellets automatically, they are rotated about their axis. A flat beam is focused onto a nominal generatrix of the pellet. The returned light coming from an elongate zone, this being the zone illuminated on a defect-free pellet, is collected. The intensity is detected, point by point, along the zone and the defects are deduced from the variations in the intensity. To this end, the points of each zone are determined in which the intensity of the returned light lies between two adjustable normality thresholds, the transition points are stored in memory, and the limits of each defect and its type are determined by neighborhood analysis.