Optical measurement of particle concentration
US4928153A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1987 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | Apr 6, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/47
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method and apparatus for measuring concentration of micrometer- and submicrometer-size particles on a carrier as a function of Mie scattering in the visible spectrum. A collimated beam of white light is directed through a carrier onto the particles, with a portion of the light energy being scattered and a portion transmitted according to Mie scattering theory. Particle size, index of refraction and measurement wavelength are selected such that scattering extinction varies essentially monotonically with the ratio of particle size to illumination wavelength. Particle concentration is indicated as a function of a difference between light scattered at two wavelengths at opposite ends of the visible spectrum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.