Acoustic fire detection circuit responsive to microcapsule ruptures

摘要

For the early detection of an abnormal rise in the temperature in an enclosure to be protected, a large number of micro-containers are arranged in the enclosure. These micro-containers are, for example, incorporated in the paint coating the walls of the enclosure. The micro-containers are filled with an extinguishing gas and produce when they burst a characteristic noise which is detected by microphones. The installation also comprises for the purpose of avoiding false alarms and achieving an adequate discrimination of the useful signal from that produced by the normal surrounding noise, a filtering and processing circuit which operates in an essentially digital manner.