Gravity sedimentation method for determining particle size - measures progress of particles in fluid optically, by system with optical fibre and lens mounted on platform

摘要

By placing the particles in a suitable fluid their size may be evaluated by their progress down the fluid. This progress is monitored by shining light across the vessel containing the fluid (2) and measuring the light received on the other side by means of a photo-electric detector (1). Light from the lamp (9) is guided to the lens (4) by an optical fibre (5) and the lens and the detector are mounted on a platform which can be moved up and down the vessel to measure the opacity at different heights. A sliding shutter controls the amount of light sh ining across the fluid to achieve accurate results.