Patent ID: 7449694
Filing Date: 2008-11-11
Classification: G01N

Abstract:
1. An optical gas sensor comprising a gas chamber for housing a sample gas; a gas opening for injecting the sample gas into the gas chamber or for exhausting the sample gas from the gas chamber; an infrared optical source for projecting infrared toward the sample gas; and an infrared sensor for sensing the intensity of the infrared which has passed through the sample gas, characterized in that: the wall of the gas chamber is composed of two opposing concave mirrors having different focusing distances but a common focus, and the concave mirrors have curvatures such that the incident light which is parallel to the axis of the concave mirror reflects on the surface of the concave mirror and passes through the common focus of the concave mirror, and that the incident light, which has passed through the common focus of the concave mirror reflects on the surface of the concave mirror and propagates parallel to the axis of the concave mirror.