| abstract |
(57) [Summary] [PROBLEMS] To reduce the size and cost of a sensor for measuring carbon dioxide in breathing air, and at the same time, to improve measurement accuracy and responsiveness. SOLUTION: A tubular sensor main body 1 is divided into three parts in the axial direction, a light emitting element 2 and a light receiving element 3 are provided at both ends, respectively, and a breathing passage 4 is provided at a center part. The sensor body 1 is attached to the face under the nostril, and exhaled air discharged from the nostril is introduced into the respiratory air passage 4 and passed through an optical axis connecting the light emitting element 2 and the light receiving element 3 to measure carbon dioxide in the respiratory air. I do. |