Fire sensing system, process for sensing fire and environment monitor

A fire sensing system, comprising:

• a plurality of band-pass filters separating infrared radiation from a source of infrared radiation into a plurality of wavelength bands;
• an infrared sensor sensing an infrared radiation which has passed through each of said band-pass filters, one of the wavelength bands comprising a CO.sub.2 -molecular resonance radiation wavelength band;
• a signal processor determining whether a disastrous fire occurs or not in response to outputs of the infrared sensors and a change in a ratio of the outputs of the infrared sensors, and
• wherein said signal processor computes the blackbody radiation intensity of the sensing band of one of said infrared sensors which senses a CO.sub.2 -molecular resonance radiation band in response to said one of said infrared sensors, and said signal processor compares the computer blackbody radiation intensity with an output of said one of said infrared sensors in order to sense CO.sub.2 -molecular resonance radiation and determines an occurrence of a disastrous fire when sensing the CO.sub.2 -molecular resonance radiation.

A process for sensing a fire, comprising the steps of:

• computing the temperature of an infrared source from a ratio of outputs of a plurality of infrared sensors sensing at least two wavelength bands of an infrared radiation from a monitored area;
• computing the intensity of infrared radiation of one of the wavelength bands from said computed temperature;
• computing a heating area from the intensity of the infrared radiation and an output of an infrared sensor sensing said one of the wavelength bands;
• utilizing one of the infrared sensors for sensing a CO.sub.2 -molecular resonance radiation wavelength band;
• computing the blackbody radiation intensity of the infrared source in a CO.sub.2 -molecular resonance radiation wavelength band from the temperature and the heating area of the infrared source both computed from an output of the other infrared sensor in accordance with said temperature and heating area computing steps;
• and
• comparing the computed blackbody radiation intensity with an output of said one of said infrared sensors sensing CO.sub.2 -molecular resonance radiation and determining an occurrence of a disastrous fire when sensing the CO.sub.2 -molecular resonance radiation.

An environment monitor, comprising:

• a plurality of band-pass filters separating infrared radiation from a monitored space into a plurality of wavelength bands;
• an infrared sensor sensing infrared radiation passing through each of said band-pass filters, one of the wavelength bands comprising a CO.sub.2 -molecular resonance radiation wavelength band;
• a signal processor determining the occurrence of fire and computing a temperature of the infrared radiation from the monitored space from outputs of the infrared sensors of the wavelength bands and a change in a ratio of said sensing outputs;
• and
• a chopper periodically chopping the infrared radiation from the infrared source in order to provide the infrared radiation to said infrared sensors.

A process for sensing a fire, which comprises the steps of:

• computing the temperature of an infrared source from outputs of a plurality of infrared sensors sensing at least two different wavelengths by comparing the ratio of said outputs;
• computing the blackbody radiation intensity of at least one of said different wavelengths from said computed temperature;
• computing a heating area of said infrared source from said blackbody radiation intensity and output from said infrared sensor sensing said at least one of said different wavelengths;
• and
• determining the existence of a uncontrolled fire from changes in said computed temperature and said computed heating area.

A fire sensing system, comprising:

• a plurality of band-pass filters separating infrared radiation from a source of infrared radiation into a plurality of wavelength bands, wherein one of said band-pass filters passes a CO.sub.2 -molecular resonance radiation wavelength band;
• a plurality of infrared sensors sensing said separated infrared radiation which has passed through each of said band-pass filters;
• a signal processor for determining a temperature and a heating area of said source of infrared radiation and determining the existence of an uncontrolled fire based on changes in said temperature and said heating area;
• and
• a signal processor for determining the existence of a flame in said source of infrared radiation by comparing an output of a sensor sensing said CO.sub.2 -molecular resonance radiation wavelength with a value predicted by said temperature and said heating area for determining the existence of an uncontrolled flaming fire.

A fire sensing system, comprising:

• a plurality of band-pass filters separating infrared radiation from a source of infrared radiation into a plurality of wavelength bands;
• a plurality of infrared sensors sensing said separated infrared radiation which has passed through each of said band-pass filters;
• a signal processor for determining a temperature and a heating area of said source of infrared radiation and determining the existence of an uncontrolled fire based on changes in said temperature and said heating area;
• and
• a chopper periodically chopping said infrared radiation from said source of infrared radiation in order to provide said infrared radiation to said infrared sensors.