Open photoacoustic sensor as smoke detector

We describe the use of a photoacoustic aerosol sensor for fire detection applications. The sensor is based on a cylindrical resonant chamber which is completely open on both sides in order to allow the smoke to enter it by pure diffusion. The sensor is equipped with a resonance tracking system that continuously monitors the changes in the resonance frequency caused by environmental conditions or an actual fire situation. The results show that our sensor has a very good response to smoke originating in open flaming combustion processes, which are hard to detect with commercially available sensors, and a low cross-sensitivity to the usual false alarm sources making it an ideal candidate to fill in an existing gap in the fire detection devices.