Research On Smoke Density Measurement System Used In Fire Control

Smoke density is a physical quantity and it is extremely important in the field of fire science research.During the initial stage,fire smoke will hinder people from escaping and putting out the fire,which may cause great harm to the safety of life and property.The deposition of fire smoke will pollute the surface of furniture and equipment.The damage of fire smoke to the environment is also greatly.Harmful gas of fuel decomposition diffusion into the air,it not only can cause air pollution,but also can harm human body.Thus the study for fire smoke becomes urgently.In this study,the measurement of the smoke concentration is a basic and important part.All of the parts of fire smoke control,performance design,personnel evacuating,material safety evaluation,dignosis of combustion and fire detection research are needed to measure accurately on the smoke density.Through the analysis of the related problems of the smoke density,refer to the related literature at home and abroad,this study will summarize the measuring instrument parameter specificationuse through various smoke concentration measurement standards and literature research.On the basis of Lambert-Beer principle in the law of light,the calculation process of smoke density is deduced,the premise of the Lambert-Beer principle is:The light is monochromatic light and receiving the output intensity does not include the forward scattering light component.With these parameters as the guidance,design of optical system,the usage of infrared light as the light source is easy for calibration.To avoid the interference of light scattering,design of collimating and correcting the measuring result.This paper avoids the machinery error caused by the shootoptical structure through the establishment of design characteristics of extinction instrument performance requirements;with the cooperation arrangement of optical elements,the circuit system can be concentrated in one integrated circuit system,which overcomes the defects of poor anti-interference ability caused by the long distance transmission;through the calculation and test of in-depth analysis,the paper makes designs for the laser driver circuit,photodiode preamplifier,secondary amplifier and instrumentation amplifier.The design of smoke concentration measurement system based on light extinction method in this paper achieves high performance and excellent technical indicators.This system also has the following characteristics:measurement of optical path can be adjusted flexibly,which can be adapted to various fire experiments;the low cost is easy for production.The measurement system In accordance with the Standard for smoke box,can basically solve mostsmoke concentration problems in fire experiments,which has broad application prospects.