| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce sensitivity changes due to moisture, in the head of the detector of an infrared absorption type humidity fluctuation meter. SOLUTION: A floodlight projection head 2 is composed of a parabolic mirror 14 and a lamp 5. A light detecting head 1 is composed of a light detection lens 11, having a short focal distance and increased in edge thickness, an optical filter 10, a slit 12 provided between of optical filter 10 and the light detecting lens 11 and a photodetector 13.</p> |
