| 摘要 |
<P>PROBLEM TO BE SOLVED: To allow low density smoke caused by fire to be surely detected without causing an error due to particulates other than a fire. <P>SOLUTION: A fan 36 sucks external air through an inlet 14 of a housing 12, makes the air pass through a smoke detection chamber 24, and then exhausts it from an exhaust port 16. A light receiving unit 28 is installed and fixed in the smoke detection chamber 24. A light emission unit 26 is arranged on a light-emission swivel base 46, and rotated so as to change a receiving light scattering angle caused by crossing of a light receiving optical axis 32 and light emission optical axis 30. A sensor circuit section stores a reference index in advance based on a reference scattering light quantity corresponding to change of scattering angle of light received when light of prescribed wavelength is radiated to particulates of a prescribed kind of smoke, obtains a receiving light scattering quantity which is detected by the light receiving unit 28 in association with a receiving light scattering angle at each time point and changes with rotation of the light emission unit 26, and determines a fire based on the index. <P>COPYRIGHT: (C)2012,JPO&INPIT |
