| 摘要 |
A detector inlet 1 for providing a sample from gaseous fluid which carries particulates to an analytical apparatus for detecting a substance of interest, the detector inlet comprising a plenum 11 with a sampling volume 10, a sampling inlet 14 arranged in the plenum to collect samples of the gaseous fluid from the sampling volume and to provide the samples to the analytical apparatus, and a flow director arranged to create circulatory flow of the gaseous fluid around the plenum to encircle the sampling inlet and thereby vary spatial distribution of the particulates carried by the gaseous fluid to increase a relative proportion of the particulates carried past the sampling inlet without entering the sampling volume. The detector inlet further comprises flow passage, a flow inlet 2 and a flow outlet 4. The sampling inlet may be a pinhole. Ideally, the flow director comprises a curved wall of the plenum, a fin or groove within the wall of the plenum. |
