GB798144A - Method of and apparatus for optically detecting the presence of solid material in transparent liquids - Google Patents

Abstract

798,144. Turbidometers. GENERAL ELECTRIC CO., Ltd. Feb. 7, 1957 [March 16, 1956], No. 8363/56. Class 97(3) Solid particle impurities in a transparent liquid in a transparent container are detected by spinning the container in one direction to cause the liquid to swirl round therein and then rotating it relatively slowly in the opposite direction in a light beam whereby the impurities even if, initially, on the bottom of the container, may be observed and distinguished from, for example, particles on the outside of the container. In the form illustrated each liquid container is an ampoule 9, Fig. 2, secured. by spring clips 23 in a tubular nolder 8 rotatable by a wheel 11 in a bearing 7 carried on a travelling band 4. At one point in the travel of the band the wheel 11 is moved into contact with a motor driven rubber tyred wheel 14 being held into contact therewith by an idler wheel 17. At a later point in the travel the wheel 11 encountered a friction pad 24, Fig. 3, which, as a result of the travel, rotates the ampoule and its holder in a direction arranged to be the reverse of that produced by the wheel 14. At this point the ampoule is illuminated by a sodium vapour lamp 25 and observed through a lens 32. The axis of the ampoule is slightly inclined to avoid distracting reflections from the glass. Shields 30, 31 confine the light from the lamp. A dark background for observation is provided by a shiny black screen 28 and a matt black screen 29.