Beam Detector : Components, including any reflectors, necessary for the detection of smoke by the attenuation of an optical beam external to the fire detector
Solutions Fire Safety Ltd, Fire Safety Glossary: An A - Z of definitions regarding fire safety terms and vocabulary, Solutions Fire Safety Ltd, UK 2012. http://solutionsfire.co.uk/Fire-literatures-PDF/Fi re-Safety-Glossary.pdf, (Fr Sfty - Brit) {465}