This European Standard specifies general requirements for the construction, testing and performance of electrically operated apparatus for the detection of combustible gases, designed for continuous operation in a fixed installation in domestic premises. The apparatus may be mains or battery powered.Additional requirements for apparatus to be used in recreational vehicles and similar premises are specified in EN 50194-2.NOTE 1 For caravan holiday homes EN 50194-1 applies.This European Standard specifies two types of apparatus to operate in the event of an escape of town gas, natural gas or liquefied petroleum gas (LPG):- Type A apparatus - to provide a visu