光声火灾探测系统新模型

普通光声气体探测模型因其实时性能差及波段要求高而不适用于火灾报警系统。本文介绍一种基于光声原理的CO在线测量的火灾报警模型。光声腔中采用纯CO气体代替气体采样，通过红外光源与光声腔之间的吸收路径测量火灾气体。一旦火灾气体经过该路径，将在不同吸收线上导致到达光声腔辐射量的减小。因此，只有与光声腔中气体一致的成分才能减弱初始光声信号，而信号变化代表了CO的存在。

New Model for a Photoacoustic Fire Detection System

Common photoacoustic gas detection model is not suitable for fire warning because of poor real-time performance and high wavelength qualifications. This paper describes an online CO detection system model for fire warning based on photoacoustic principle but with a different system design. The photoacoustic cell was filled with pure CO instead of gas sample. Fire gases were measured in an absorption path set between the IR source and the cell. Once fire gases pass through the path, they will reduce the radiation that reaches the cell in different absorption lines. Thus only the species identical to the gas in the PA cell can attenuate the initial photoacoustic signal. This signal variation indicates the presence of CO.