Provides efficient reliable detection using the light scatter sensing principle with rapid response to a fire signal. The intelligent sensor data is evaluated by the Protec-AlgoTec 6000 interactive programmable algorithms, designed to give maximum sensitivity to smoke detection, with high resistance to false alarms due to high air velocity, insects, dust and R.F. interference. Providing early warning of a fire condition particularly for slow burning fires, the 6000/OP are an ideal general-purpose smoke sensor for offices, shops, corridors, factories, warehouses and computer rooms.