| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a gas analyzer which can be miniaturized and simplified by a method wherein a gas which contains a gas to be analyzed is made to flow into a space between a light source, a photodetector and a concave reflection g mirror and the degree of its characteristic absorption is measured. SOLUTION: Infrared rays S1 which are radiated from a light source 4 arranged in the focal position, on one side, of an oval reflecting mirror 2 are reflected by the oval reflecting mirror 2 from a passage hole 17, and reflected light S2 is condensed, via a hole 18, by a photodetector 5 arranged in the focal position, on the other side, of the oval reflecting mirror 2. That is to say, a luminous flux which is radiated from the light source 4 is turned down once by the oval reflecting mirror 2, and it is possible to obtain a doubled optical path length. In addition, since the angular aperture of an optical path regarding infrared absorption can be made large, the transmission efficiency of a light-emitting operation can be increased. In this manner, since the optical path regarding the infrared absorption can be formed so as to be turned down, even a small infrared gas analyzer can absorb infrared rays sufficiently. When two outputs of the photodetector 5 are computed and processed, the concentration value or the warning of CO2 gas is output, and an air conditioning operation can be controlled surely.</p> |
