| 摘要 |
A cross pipe pollution detector apparatus is disclosed for use as an aspirated smoke detector comprising a pair of air supplied pipes (5, 6) for receiving sample air aspirated therein from an area under pollution or smoke surveillance. The pipes (5, 6) being connected in an X formation junction with air flow to and from two of the arms through the junction (7), a light projector and a receiver positioned in respective other arms, whereby unscattered light from the projector is directed down one of the flow paths and not towards the receiver and is arranged across the path of the other flow path at the junction (7) formed in the pipes, the arrangement being such that the light in the junction will impinge upon particles appearing in the junction (7) to scatter the light thereby to be received by the detector. |
