SEEING THE LIGHT

摘要

Optical detectors generally have difficulty discriminating between steam and dust particles, and those caused by combustion. A new approach from Nittan Group involves dual wavelength detectors which can help reduce false alarms. It is generally accepted that optical smoke detectors - using the scattered light principle -are today taking over the market where once ionisation smoke detectors dominated. This is because the use of radioactive material for ionisation smoke detectors has increasingly become controlled by regulation and legislation, and its use and handling are restricted. Generally speaking, the scattered light technology used for commercial detectors is unable to discriminate larger size particles -like steam or dust, that are major causes of false alarms - from particles generated by combustion. Furthermore, the optical detector is insensitive to flaming fires when compared to an ionisation detector.