| 摘要 |
PURPOSE:To prolong the effective section of a measuring cell so as to make a gas analyzing instrument high in sensitivity and compact in constitution, by forming the cross-sectional shape of the measuring cell parallel with the optical path to have an angular shape of odd vertices having an inner surface whose width is almost the same as the width of the optical path when viewed from the incident direction. CONSTITUTION:A measuring cell 1 is constituted in such a way that its cross-sectional shape parallel with the optical path (a) is formed to have an angular shape with odd vertices having an inner surface, whose width is almost the same as the width (l) of the optical path (a) when viewed from the incident direction and its entire inner surface except cell windows 5 and 6 is constituted to mirror surfaces M1 and M2 so as to reflect the optical path (a) with the mirror surfaces M1 and M2. Lights radiated from a light source 2 are intermittently discontinued by a chopper 3 and vertically made incident to the cell window 5. The lights entering into the measuring cell 1 are reflected by the mirror surfaces M1 and M2 and made incident to a detector 4 after passing through the cell window 6. The light made incident to the mirror surface M1 from the cell window 5 and the light reflected by the mirror surface M1 are almost superposed upon each other and the light made incident to the mirror surface M2 and the light reflected by the mirror surface M2 are almost superposed upon each other, and thus, doubled sensitivity is obtained. |
