An apparatus (so-called ‘flame detector’) consisting of passive infra-red and ultra-violet sensors, an optical filter, an evaluation unit, three output relays (fire alarm, fault and auxiliary relay) and a three colour status LED (indicating normal operation, fire and fault condition), in a cylindrical housing with a diameter of approximately 12 cm and a length of approximately 25 cm. Its operating range is 18 to 30 V DC.
The apparatus is a component of a fire alarm system. The sensors simultaneously detect the infra-red and ultra-violet radiation emitted by a fire. If the radiation emitted is above a certain threshold, the apparatus sends an electrical signal via the fire alarm relay to a fire alarm apparatus. The fire alarm apparatus is not included upon presentation.
[1][1]. https://eur-lex.europa.eu/eli/reg_impl/2014/550