A PARTICULATE DETECTOR

摘要

A particulate detector (10) comprises a radiation source (12) arranged to emit radiation in at least first and second predetermined wavebands towards a sampling region (18) suspected of containing particulates, and a detection element (14), shielded from the radiation source (12), and arranged to detect radiation from the sampling region (18) at at least first and second instances. The radiation source (12) is such that the emissions in the wavebands temporarily overlap. The detector is such that, at the instances at which the radiation is detected, the relative contributions from the emissions in each predetermined waveband are distinguishable, thereby allowing characteristics of the particulates to be determined. The radiation source (12) may comprise a light emitting diode (24).