A system and method is provided for an improved sensor for detecting particles in air such as smoke particles from a fire. The detector includes a laser diode that generates a light beam that is spread by a lens to fill a specific area of the interior of a sensing chamber before entering into a light...http://www.google.fr/patents/US7847700?utm_source=gb-gplus-shareBrevet US7847700 - System and method for an optical particle detector
System and method for an optical particle detector
