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:
Jul. 18, 2000
Filed:
May. 25, 1999
Gerhard Kreikebaum, San Bernardino, CA (US);
Venturedyne, Ltd., Milwaukee, WI (US);
Abstract
A particle sensor operates in ambient air at an ambient air temperature and includes (a) a light source projecting a beam of light, (b) a light trap aligned with the beam of light and comprising at least one light-energy-absorbing surface at a surface temperature, (c) a nozzle flowing particle-entraining air through the beam of light, and (d) an opto-electrical system detecting light scattered by a particle. In the improvement, the sensor includes a cooling apparatus in heat transfer relationship to the surface and absorbing heat from such surface. The surface temperature is maintained at or below a value which substantially eliminates thermally-induced electro-optical disturbances in the sensor. A new method for reducing electrical noise detected by an opto-electrical system in the particle sensor includes providing a cooling apparatus in heat transfer relationship to the surface and transferring heat from the surface to the cooling apparatus at a rate which limits the surface temperature to a value which substantially eliminates thermally-induced electro-optical disturbances in the sensor.