Abstract: A method of measuring sizes of particles suspended in a liquid using optical mixing spectroscopy of scattered light and an apparatus for implementing the method are disclosed. The method involves making measurements by a fiber optic probe introduced into a medium under investigation, the probe including several multiple or single mode optical fibers. One of the optical fibers transmits light into the medium, while the other optical fibers transmits scattered light to a device for providing spatial coherence of the light and then to a light detector. Auxiliary optical fibers are used to determine the relationship between spectral line widths of multiple and single light scattering when measurements are conducted in very turbid media and for determining particle sizes from multiple rather than single scattering spectrum.

Abstract: The invention relates to processes for measuring and controlling particle sizes in micro- and nanoemulsions, colloidal solutions and suspensions of particles in liquids and gases. The invention is applicable in chemical processes, in particular, in petrochemistry, transportation of petroleum products, oil and gas, in food and medical industries, medical research, for producing nanoparticles for electronic and electrical industry, controlling the state of operating fluids in mechanical and power engineering, i.e. for controlling the processes for producing or using colloidal solutions, emulsions and suspensions of solid or liquid particles. A new method of measuring sizes of particles suspended in a liquid using optical mixing spectroscopy of scattered light and an apparatus for implementing the method are disclosed. The method consists in making measurements by a fiber optic probe introduced into a medium under investigation, the probe comprising several multiple or single mode optical fibers.