Study On Quantitative Monitoring Technology Of Fire Gaseous Products Based On FT-IR

Fire disaster is one of the frequent and devastating disasters. It occurs throughout villages and cities, causing great lost and sufferings. In all the fire, it will have a large number of toxic and harmful gases, which is the most important threat to man's survival. In some fire-science-related research, it also needs to monitor concentration of gases for research demand. So it is highly desirable to monitor the concentration of those gases. But current fire detection devices can't meet the following requirement: real-time, on-line, multi-component, high-precision. In view of the above requirements, the multi-component on-line quantitative monitoring system based on Fourier transform infrared spectroscopy (FT-IR) was researched, and a prototype was built.In this paper, five gases(CO,CO₂,NO,SO₂,NO₂) were selected to be detected. Quantitative analysis methods based on FT-IR was be used. Using FT-IR spectrometer and multiple reflections gas cell, the spectrum of gas was collected. The concentration of each gas was measured by using the quantitative model of gases( CO,CO₂,NO,SO₂,NO₂) which describes the relationship between concentration data of gases and spectra data of gases.The process of research follows the steps of method of building quantitative model. A series of operation methods was designed for calibration, validation and test. According to the principle of chemometrics and characteristic of fire detection, partial least squares (PLS) method was selected as quantitative method of the gases( CO,CO₂,NO,SO₂,NO₂). And error analysis method was used to improve the qualification of steps of building quantitative model. Finally, the measure system was tested. The results shows that the measurement system can achieve quantitative monitoring of the concerned gases with a better measurement accuracy, which meets the measurement accuracy of each component gas in 2% of the full scale (±2 % F .S .) within the design requirements.