DS EN 50131-2-4:2008
DS EN 50131-2-4:2008 Alarm Systems - Intrusion And Hold-Up Systems - Part 2-4: Requirements For Combined Passive Infrared And Microwave Detectors Defines combined passive infrared and microwave detectors installed in buildings and provides for security grades 1 to 4, specific or non-specific wired or wire-free detectors, and uses environmental