Patent ID: 6512230
Filing Date: 2003-01-28
Classification: G01N

Abstract:
An apparatus for analyzing a gas mixture for one or more gas components that may be present in the gas mixture, the analysis of the one or more gas components being carried out on the basis of radiation absorption properties, said apparatus comprising:a radiation source for providing a radiation beam; a measuring chamber (6) for receiving a gas mixture, said measuring chamber having at least one radiation transmissive window (7a,7b) for the radiation of said radiation source, radiation from said radiation source passing through the gas mixture in said measuring chamber; a first detector (1) for receiving radiation that has passed through said measuring chamber; a first optical interference band pass filter (3) interposed in front of said detector along a path of said radiation beam, said first filter having a surface to which is applied radiation that has passed through said measuring chamber, said first filter having a radiation wavelength transmission band (&lgr;1) for transmitting radiation of the transmission band wavelength through the filter to said first detector, said surface reflecting radiation having wavelengths outside said radiation wavelength transmission band, said first filter being movable to a plurality of positions inclined with respect to the radiation beam for altering said radiation wavelength transmission band of said first filter, movement of said first filter causing movement of the radiation reflected from said surface; and a second detector (2) positioned with respect to said first filter for receiving radiation reflected from said surface when said first filter is moved to a given one of said plurality of positions of said first filter.