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).

Abstract: In a system for detecting gaseous emissions (10), a housing (20) encases a mechanical member such as a flanged coupling (21) of a closed mechanical system which contains a fluid such as a gas (11) and receives gas (11) escaping through the flanged coupling (21). A sensor (26) extends through the housing (20) into a cavity (22) formed by the housing (20). A semipermeable membrane (28) forming the union between the sensor (26) and housing (20) allows gas (11) encased by the housing (20) to slowly pass from the housing (20) while preventing foreign matter from entering the housing.

Abstract: This invention relates to an apparatus (10) for, and a method of, collecting and analyzing a sample of exhaust gases (16) from a mobile exhaust source. A funneling member (18) is attached to a vehicle (12) for concentrating exhaust gases (16) discharged by a moving exhaust source. The vehicle (12) is positioned behind the mobile exhaust source such that the funneling member (18) is within a stream of exhaust gases (30) being discharged by the mobile exhaust source. As the exhaust gases (16) pass through the funneling member (18), a sampling tube (22) extracts a sample of the concentrated exhaust gases (16) and routes them to an analyzing means (26) for analysis of the sample.