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:
Aug. 25, 1998
Filed:
Jan. 31, 1997
John Kert, Pismo Beach, CA (US);
Robert Stephens, Sterling Heights, MI (US);
Michael D Jack, Goleta, CA (US);
Envirotest Systems Corp., Sunnyvale, CA (US);
Abstract
A system (10) for simultaneously measuring temperature and CO, CO.sub.2 and HC gas content of vehicle (11) exhaust detects and analyzes a beam of infrared electromagnetic radiation (21) projected through a plume (13) of vehicle exhaust to assess the concentration of CO, CO.sub.2, and HC in the vehicle exhaust and detects and analyzes infrared electromagnetic radiation (15) emitted by the plume (13) to assess the temperature of the plume (13) and, consequently, whether the vehicle's (11) catalytic converter is operating in the cold or hot mode. Essentially simultaneous measurement is taken by intermittently interrupting the beam (21) of projected infrared electromagnetic radiation and detecting and analyzing the emitted infrared radiation (15) during the intervals of interruption when the beam (21) is not projected through the plume (13). Intermittent projection of the beam (21) is accomplished by insertion of a chopper wheel (22) between an infrared beam projector (20) and the plume (13).