| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform accurate gas detection with a reduced drift of an electric signal by reducing deformation of a gas container due to a temperature change or external stress and thereby suppressing a change in a speckle pattern. SOLUTION: Recessed parts 23 and 24, with their inner wall surfaces adapted to be light diffusion surfaces 11, are provided in first and second blocks 21 and 22, respectively, made by bisecting a hard material. A space formed by putting together the openings of the recessed parts 23 and 24 serves as the gas container 3 for containing a detected gas. A swelled opening part 24a is provided by forming the opening of the recessed part 24 in the second block 22 so as to be partly larger than the opening of the recessed part 23 in the first block 21, and the opening part 24a is closed with a lid member 25. A light source 5 is fixed so as to make surface contact with a mounting surface 21 of the first block 21 and with an outer wall surface of the lid member 25. A photoreceptor 9 is fixed so as to make surface contact with an outer wall surface of the first block 21 or second block 22. The light source 5 has a heat radiating structure on its non-contact surface 34b side with respect to the mounting surface 21b of the first block 21 and the outer wall surface of the lid member 25.</p> |
