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1. (WO1994028392) APPARATUS AND METHOD FOR DETERMINING THE SIZE OF PARTICLES USING LIGHT SCATTERING

Pub. No.:    WO/1994/028392    International Application No.:    PCT/US1994/005968
Publication Date: Dec 8, 1994 International Filing Date: May 26, 1994
IPC: G01N 15/02
Applicants: THE DOW CHEMICAL COMPANY
BENEDETTO, Elizabeth, E.
LYONS, John, W.
WOOD, Stewart, P.
Inventors: BENEDETTO, Elizabeth, E.
LYONS, John, W.
WOOD, Stewart, P.
Title: APPARATUS AND METHOD FOR DETERMINING THE SIZE OF PARTICLES USING LIGHT SCATTERING
Abstract:
An apparatus and method are disclosed which allow the size of a particle (20) suspended in a medium to be determined virtually independent of the materials' refractive index. The apparatus includes a means (12) for producing a beam of collimated light (22), a means (13) for exposing the particles (20) to the collimated light (22), thereby scattering the light, a detector (14, 31), and a means (17, 41, 43) for preventing any of the light which was scattered by the particles (20) from reaching the detector (14, 31). The method of the invention comprises passing the medium containing the particle (20) through a beam of collimated light (22), so that the light which contacts the particle (20) will be scattered; deterring the light which was scattered by the particles (20) from being detected; detecting the light which was not scattered by the particle, and determining the size of the particle (20) from the decrease in the light intensity incident on the detector (14, 31).