| 摘要 |
<p>The improved sample chamber includes an elongated hollow tube (12) closed at one end (14) and having specularly-reflective inwardly facing surfaces (16). A source (26) of radiation and a detector (28) of radiation are mounted side by side in the open end of the hollow tube, both facing the closed end. A plurality of filtering apertures (20) are formed in the tube (12), and each aperture is covered by a sheet (22) of a semipermeable membrane that serves to prevent airborne particles larger than a predetermined size from entering the chamber while not interfering with the free diffusion of the gas to be measured into and out of the chamber. The use of an elongated hollow tube that is closed at one end results in no loss in the efficiency with which the radiation is conducted from the source to the detector while decreasing the external length of the chamber by 50 percent.</p> |
