Patent · US Expired

Process and apparatus for identifying or characterizing small particles

US4548500A · kind A · utility

41Cited by
4References
16Claims
0Family size

Inventors

Key dates

Filing dateJun 22, 1982
Grant dateOct 22, 1985
Priority date
Expiry dateJun 22, 2002

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2015/019
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An apparatus and process are described for the characterization and/or identification of individual microparticles based upon the measurement of certain optical observables produced as each particle passes through a beam of light, or other electromagnetic radiation. A fine beam of, preferably, monochromatic linearly polarized light passes through a spherical array of detectors, or fiber optics means to transmit incident light to a set of detector means, and a stream of particles intersects the beam at the center of the spherical array. Selected observables calculated from the detected scattered radiation are then used to recall specific maps, from a computer memory means, one for each observable. The common overlap region of said maps yields characterizing or identifying particle physical parameters such as size, mean refractive index, and shape. A method for rapidly discriminating non-spherically symmetric particles is also disclosed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.