The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 20, 1979
Filed:
Aug. 25, 1977
Robert A Young, Chatsworth, CA (US);
Xonics, Inc., Van Nuys, CA (US);
Abstract
Apparatus for the measurement of hair-like particles, such as measurement of the amount of asbestos fiber in air. Apparatus including a source of a polarized beam of radiation directed to a scattering zone and a detector for detecting radiation of the beam scattered from the zone. A device at the zone, typically a pair of spaced parallel plates with an electric field therebetween, for orienting the hair-like particles parallel with each other and substantially perpendicular to the incoming beam of radiation, and a drive mechanism for rotating the polarized beam relative to the oriented particles to a first position with the polarization of the beam parallel to the particles and to a second position with the polarization of the beam perpendicular to the particles. A modulation reference signal and the signal from the radiation detector may be provided to a synchronous detector which produces an output varying as a function of the scattering produced by the hair-like particles and hence a function of the quantity of the particles in the zone. The scattering is much larger when the direction of the electric vector in the polarized beam is parallel to the long axis of the aligned hair-like particles.