Patent · US Expired

Apparatus for detecting fibrous particle sizes by detecting scattered light at different angles

US4737648A · kind A · utility

16Cited by
4References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 25, 1986
Grant dateApr 12, 1988
Priority date
Expiry dateSep 25, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2021/4711
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

The invention comprises apparatus capable of unambiguous determination of the length and diameter of fibrous particles, especially asbestos fibres, based on near-forward scattering of light by fibres aligned in a hydrodynamically focused gas flow. Three portions of scattered light are detected, two portions perpendicular to the fibre axis and one aligned with it, from which length and diameter can be independently determined. This independence is achieved by allowing only selected parts of the light scattered within certain selected ranges of angles to reach each detector. A two-detector instrument capable of accurate determination of fibre diameter is also described.

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