Optical analyzing instrument having vibrating trough

摘要

An instrument for optically measuring and analyzing samples of particulate material includes a chute for conveying the samples through a light beam by which the measurements are made and a trough positioned at the bottom of the chute. The trough supports a column of the particulate material in the chute and acts as a gate to prevent the particulate material from flowing out of the chute. The trough is mounted on a vibrator and during the measurement operation vibrates to cause the particulate material to flow out of the chute. When vibrating, the trough transmits vibrations up through the column of particulate material in the chute to maintain the column in a free flowing condition and to prevent bridging.