双波长气溶胶粒径传感方法及其火灾烟雾探测器

提出了双波长光散射气溶胶粒径传感方法,设计实现了采用该方法的双波长火灾烟雾探测器。使用短波长和长波长的双波长光源,通过计算其光功率比值,利用其与中值粒径的关系函数获得气溶胶粒径,并根据不同粒径下的气溶胶浓度分别给出大小不同粒径的火灾烟雾或干扰气溶胶提示。因而,不仅可以有效区分大小不同粒径的火灾烟雾气溶胶,以正确探测火灾,而且能够识别微米级的大粒径干扰粒子,降低火灾误报率,可以应用于飞机等航空器空中密闭的特殊环境。

Sensing method of aerosol median diameter based on dual wavelength and its application in fire smoke detectors

This paper proposes an optical sensing method to measure the median diameter of aerosols by dual wavelength scattering, and designs a fire smoke detector by this method. A short and a long wavelength incident lights are applied in the detector, and the ratio of scattering signals from dual wavelengths is used to calculate the median diameter of aerosols. Besides the aerosol concentration, the median diameter of aerosols is utilized to distinguish fire smoke and non-fire aerosols. The detector triggers different levels of warning base on comprehensive analysis of the concentration and the median diameter of aerosols. Therefore, the detector with dual wavelength technology could measure the particle size of fire smokes effectively and detect a fire correctly. Furthermore, it is particularly applicable in a closed environment like a plane in the air, since its unique ability to resist the false alarms by identifying non-fire aerosols consisting of big particles in micrometers.