This document is for combined passive infrared and 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 document does not include requirements for detectors intended for use outdoors. The purpose of the detector is to detect the broad spectrum infrared radiation emitted by an intruder, to emit microwave signals and analyse the signals that are returned and to provide the necessary range of signals or messages to be used by the rest of the intrusion alarm system. For a combined detector where both detection technologies need to be in their activated state in order to generate an alarm condition, the grade-dependent requirements of this document apply. For combined detectors which can be configured or operated such that each detection technology can generate an alarm condition independently, the grade-dependant requirements as defined in EN 50131 2 2 and EN 50131-2-3 apply, when configured accordingly. Otherwise, it is the responsibility of the manufacturer to clearly state that the detector does not comply to this document and not to EN 50131-2-2 and EN 50131 2-3 when put into such a configuration. It is essential that a detector fulfils all the requirements of the specified grade. Functions additional to the mandatory functions specified in this document can be included in the detector, providing they do not influence the correct operation of the mandatory functions. Requirements for system interconnections are not included in this document.