A method of measuring turbidity includes irradiating specimen water with a light beam, using photoelectric conversion means for subjecting to photoelectric conversion the light scattered by fine particles in the specimen water, inputting a pulse signal as an input signal 7 obtainable from the photoelectric...http://www.google.de/patents/US6184983?utm_source=gb-gplus-sharePatent US6184983 - Method and apparatus for measuring turbidity
