Gas-selective optical sensors for fire detectors

At the Center for Chemical Sensors (CCS) of ETH-Zurich, gas-sensitive membr anes have been developed during the last three years. In co-operation with PentapharmAG, Basel, and BoschTelecom GmbH, Frankfurt, the research has led to the development of a world novelty, a gas-selective fire detector calle d MagicSens. Compared with conventional fire detectors this reacts specific ally to combustible gases and considerably reduces thereby the false alarm ratio and the subsequent associated costs. Additionally, since combustible gases such as NO2 are produced during the whole first phase of afire, the f act that the membranes are very sensitive means the alarm time could be sho rtened. The signal transduction in the sensor can be produced with cheap op tical items, such as LED and photodiodes. The new fire detector will, there fore, not be more expensive than a conventional one. The product is due to be launched on the market in the near future.