External Space Detection - PIR sensors for outdoor use External detection is currently attracting much interest from installers. Benchmark tests devices from Risco, Texecom, Takex, Optex and GJD Security. The increase in interest regarding external detection is very understandable. Why wait until an intruder has gained access to a building before signalling an alarm? It makes little sense, and with police response times often being slower than hoped for - if a response is received swiftly, or indeed at all - an early warning is potentially the difference between success and failure for a system. in Hus & Hem > Kameraövervakningwith detectionoutdoorpirreviewtestutomhus