DETECTOR INLET AND SAMPLING METHOD

摘要

A detector comprising an analytical apparatus 6 for detecting a substance of interest and a detector inlet wherein the detector inlet comprises a flow passage 20 for carrying a flow of fluid and a flow director 21. The flow passage comprises a sampling volume 16 and a sampling inlet 14 for collecting samples of fluid from the sampling volume as the fluid flows past the sampling inlet and providing the samples to the analytical apparatus, wherein the flow of fluid carries particulates. The flow director is arranged to vary a spatial distribution of the particulates carried by the fluid to increase a relative proportion of the particulates carried past the sampling inlet along the flow passage without entering the sampling volume. The flow director is intended to prevent blocking or clogging of the sampling inlet by deflecting the particles such that the number of particles flowing through the sampling volume is depleted. The flow director may be a bend in the flow passage, a ramp [fig 3, 4], a change in cross-sectional area and/or shape of the flow passage [fig 5, 7] or foils [fig 6].