We have presented a sensor that can be used as a smoke
detector for fire detection applications. The sensor is based
on resonant photoacoustics and uses an open cylinder as an
azimuthal resonator chamber. As in other smoke detectors,
and in contrast to other aerosol photoacoustic sensors, our
detector has no gas flow system and the aerosol enters the
resonator chamber by pure diffusion. The big signal produced
by an actual fire situation, and therefore the low sensitivity
requirements, allows the use of this open geometry
without any noise rejection system