fremgangmsaade and apparatus for census, stoerrelsesmaaling and classification of fish

摘要

In order to count, measure sizes and classify fish, the fish are passed along an inclined track 1 in which two light detectors and corresponding transmitters (12, 13) are disposed. A fish will interrupt the beam of the light sensors (12, 13). From the relative instants at which the sensors (12, 13) sense the presence of the fish, and the time during which one sensor continues to sense the fish can be used to derive the velocity of the fish and its length. from which its overall size may be calculated. The track has a V-section and the fish may be directed into different tanks according to size. IMAGE