Research On SO₂ And CS₂ Gas Concentration Measurment Based On Absorption Spectrum

In recent years,China's atmospheric pollution has become increasingly severe.Sulfur dioxide and carbon disulfide are common atmospheric pollutant gases,which mainly come from industrial production processes and cause great harm to the ecological environment and human health.The state has increasingly stricter emission standards for the two gases,so that the detection of trace concentrations faces new challenges.Based on the absorption spectroscopy technology,this article takes SO₂ and CS₂ gas as the research object.Through the analysis of the absorption spectra of the two gases and their mixed gas in the ultraviolet region,the experimental study of the concentration measurement is carried out.?1?Explore the principle of the Beer-Lambert law of the basic law of light absorption.When the light irradiates the gas to be measured,the gas molecules generate characteristic absorption of the light.By analyzing the transmission spectrum,the concentration of the measured gas is retrieved.Differential Absorption Spectroscopy?DOAS?is based on Beer's Law,and divides the gas absorption spectrum into two parts,fast change and slow change,and uses fast-shift absorption spectroscopy to solve gas concentration.Based on the principle of DOAS measurement,an experimental system for gas concentration measurement is designed,experimental equipment is selected,and an experimental platform is set up to measure the concentrations of SO₂,CS₂,and their mixture.?2?The absorption spectrum of SO₂ gas collected in the experiment is analyzed.The absorption cross-section of SO₂ near 200 nm is the largest,and the absorption spectrum of500 data points at 206-215.98 nm is selected as the research object.Using Beer-Lambert.The relationship between the optical parameters OP and SO₂ concentration is given by the Beer-Lambert law.In order to reduce the influence of the noise signal on the concentration measurement results,the spectral data in the range of 206-215.98 nm is de-noised.Three different algorithms,peak method,summation method and integration method,are proposed to invert the gas concentration.The three methods greatly improve the measurement accuracy.?3?The absorption spectrum of CS₂ gas is analyzed.The 300 data points at202-207.98 nm are selected to obtain differential absorption spectra.The smoothing de-noising method combined with the summation method and the segmented summation method are used to calculate the CS₂ gas concentration and analyzed the detection limit.Through these two methods,solution of concentration of CS₂ standard gas with different concentration,we get two methods of linear fitting marking.?4?Conducted SO₂ and CS₂ mixed gas concentration measurement studies.Mix the two gases in different proportions,collect the absorption spectra,and observe the position shifts and peak changes of the absorption peaks.Analyze the gas absorption spectrum with a mixing ratio of 1:1,and contrast the analysis with the same volume fraction of single component gas absorption spectra in horizontal.Combining with Dalton's partial pressure law,two equations for solving gas concentration are given.In order to reduce the influence of electronic noise in the experiment,the gas solution method is improved,and the two-point equations are improved to two integral equations of the absorption bands.