Small-particulate foods may be automatically sorted at high rates using
microprocessor controlled colour sorting equipment. Particles are fed into the
chute one at a time. The angle, shape and lining material of the chute are altered
to control the velocity of the pieces as they pass a photodetector. The colour of
the background and the type and intensity of the light used for illuminating the
food (including infrared and ultraviolet options) are closely controlled for each
product. Photodetectors measure the reflected colour of each piece and
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compare it with pre-set standards, and defective foods are separated by a short
blast of compressed air. The computer can store 100 named product
configurations to enable rapid changeover to different products using an operator
touchpad.