This European Standard is for microwave detectors installed in buildings and provides for security grades 1 to 4 (see EN 50131-1), specific or non-specific wired or wire-free detectors, and uses environmental classes I to IV (see EN 50130-5). This standard does not include requirements for microwave detectors intended for use outdoors. A detector shall fulfil all the requirements of the specified grade. Functions additional to the mandatory functions specified in this standard may be included in the detector, providing they do not influence the correct operation of the mandatory functions. The standard does not apply to system interconnections.