Gas-Selective Optical Sensors for Fire Detectors

At the Center for Chemical Sensors (CCS) of ETH-Zürich, gas-sensitive membranes have been developed during the last three years. In co-operation with Pentapharm AG, Basel, and Bosch Telecom GmbH, Frankfurt, the research has led to the development of a world novelty, a gas-selective fire detector called MagicSens. Compared with conventional fire detectors this reacts specifically 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 a fire, the fact that the membranes are very sensitive means the alarm time could be shortened. The signal transduction in the sensor can be produced with cheap optical items, such as LED and photodiodes. The new fire detector will, therefore, not be more expensive than a conventional one. The product is due to be launched on the market in the near future.