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:
Sep. 04, 2001
Filed:
Mar. 18, 1999
Applicant:
Inventors:
Roger M Langdon, Colchester, GB;
Philip M Watts, Chelmsford, GB;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08B 2/100 ;
U.S. Cl.
CPC ...
G08B 2/100 ;
Abstract
A transmitter (,) is arranged to produce and focus a beam (,) on a remote focal point (,). A small proportion of resultant light (,) is back-scattered from the focal point (,) by particles or aerosols in air flowing through point (,) and returns to a receiver (,) where it is collected A detector combines resultant light (,) and reference light (,), splits the resultant light (,) and reference light (,) equally between two arms and detects which arm leads the other in phase thereby indicating the flow direction of air through focal point (,).