| 摘要 |
<p>PURPOSE:To compensate for a zero-point drift generated with changes in the attitude, by arranging more than one measuring cells and reference cells on a circumference centered on one shaft alternately to make light incident upon a photo detector alternately as passing through the cells with the rotation of a light chopper. CONSTITUTION:Four measuring cells M and four reference cells S are arranged at an equal interval alternately to be point symmetrical on the center axis. Light from a light source 1 is made parallel to the center axis with a mirror 5 to enter the measuring cells M1 and M3 passing through a light-transmitting plate 7. A gas to be analyzed runs into the measuring cells M through a path P and a measuring light enters a photo detector 3 passing through a light- transmitting plate 8, light passing hole H of a light chopper 2 and then, a mirror 6 and a bandpass filter 4. Then, the light chopper 2 is turned with a motor 9 to intercept the measuring cells M so that light is allowed to pass through the reference cells S positionally to focus each light on the photo detector 3.</p> |
