METHOD OF MEASURING PARTICLE SIZE DISTRIBUTION IN WIDE RANGE OF CONCENTRATIONS AND APPARATUS FOR REALISING SAID METHOD (VERSIONS) Russian patent published in 2012 - IPC G01N15/02 G01N21/51 

FIELD: physics.

SUBSTANCE: method involves using a lens to focus a laser beam in a cuvette containing a liquid with suspended particles; from the light scattered in the cuvette, which is converted by the lens into a parallel beam, two or more narrow beams which are scattered at different angles ranging from 90° to 180° are separated and then detected by a photodetector. The apparatus has a laser, an attenuator, a unit for interfacing the laser with optical fibre, a lens for focusing the laser radiation in the cuvette and converting scattered radiation into a parallel beam, optical fibre for transmitting the scattered radiation to the photodetector, a correlator and a computer. Between the lens for focusing the laser radiation and converting scattered radiation into a parallel beam and the photodetector, there is a switching device for separating narrow beams and transmitting said beams to the photodetector, made in form of either a diaphragm or reflecting prisms placed with possibility of movement, or in form of a diaphragm and pairs of mirrors placed with possibility of movement. In the second version, the apparatus additionally includes a first lens for forming a parallel beam of laser radiation at the output of the optical fibre, and in the first version, the apparatus also includes a second lens at the input of the optical fibre for transmitting scattered radiation to the photodetector.

EFFECT: measuring particle size distribution in a wide range of concentrations with high accuracy.

12 cl, 7 dwg