Abstract: A photoelectric apparatus for sorting articles according to size includes a vertical column of photoelectric pickups disposed adjacent to the conveyor on which the articles pass by. The apparatus includes a clock pulse generator synchronized with the conveyor, the clock pulses driving a plurality of sizing logic circuits. The signals from the photoelectric pickups are fed through a multiplexer to each sizing circuit, which counts the clock pulses while the appropriate pickups are being interrupted by an article passing by. If a given sizing circuit counts to within a predetermined number of pulses while the article passes the column, it locks out the other sizing circuits and actuates a time delay relay. The relay actuates a solenoid downstream of the column to knock the article off the conveyor and into an appropriate collection device.