| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform accurate gas detection by reducing a drift of an electric signal when a speckle pattern changes by reducing the brightness difference of the speckle pattern. SOLUTION: This gas detector 1 is equipped with a gas container 3 for containing a detected gas, a light source 5 for emitting divergent light into the container 3, a light diffusion surface 11 formed on an inner wall surface of the container 3 to diffuse the divergent light, and a photoreceptor 9 for receiving light from the container 3 concurrent with the launch of the divergent light. A light diffusion plate 21 is disposed in the container 3 to directly receive the divergent light incoming from the light source 5. The diffusion plate 21 is rotated in a prescribed cycle by a motor 23. Since the divergent light from the light source 5 is diffused by the diffusion plate 21 and the diffusion plate 21 is rotated in the prescribed cycle by the motor 23, the brightness difference of the speckle pattern of a laser beam received by the photoreceptor 9 is reduced.</p> |
