OPTICAL SMOKE DETECTOR WITH SCATTERED LIGHT COLLECTING ELEMENTS

摘要

An optical smoke detector comprising a radiation source transmittin radiation throughout a predetermined spatial region and at least one radiation receiver to which there is delivered the radiation scattered by particles located in the radiation region. One or a number of elements conducting radiation by reflection are provided and arranged such that they remove radiation, which has been forwardly scattered at an acute angle with respect to the radiation direction, at a substantially ringshaped zone about the region of direct radiation and delivers such removed forwardly scattered radiation to the radiation receiver.