1.1 This European Standard specifies the construction and testing of intrinsically safe apparatus, intended for use in potentially explosive atmospheres and for associated apparatus, which is intended for connection to intrinsically safe circuits which enter such atmospheres. 1.2 This European Standard supplements EN 50014 the requirements of which apply to intrinsically safe apparatus and to associated apparatus except as indicated in the following list. If associated apparatus is protected by a type of protection listed in EN 50014, then the requirements of that method of protection together with the relevant parts of EN 50014 also apply to the associated apparatus. The list of exclusions which follows is directly applicable to associated apparatus intended for use in situations where there is no potentially hazardous atmosphere and in other circumstances should be use in combination with the requirements of the other method of protection.