Absorption Spectroscopic Methods For Monitoring Both Sulfur Dioxide And Carbon Disulfide

Sulfur dioxide and carbon disulfide are common atmospheric pollution gases. They mainly come from daily life and industrial manufactures.They greatly threaten human health and can cause economic losses. They also play an important role in the detection of high voltage equipment fault. Enhancing the trace gas concentration measurement precision of both gases and realizing components monitoring at the same time in their compound have very important significance. Because the ultraviolet absorption spectrum has the advantages of high resolution, non-contact and on-line monitoring, it has been widely used in trace gas measurement. In this paper, the measurement methods of sulfur dioxide and carbon disulfide have been researched by using broadband absorption spectrum respectively on the basis of Beer-Lambert law. Finally, the simultaneous measurement method of the components in their compound has been researched by using broadband absorption spectrum.The measurement method of sulfur dioxide has been researched by using broadband absorption spectrum. The detection performances of SO2 have been researched within the absorption ranges around 200 nm and 300 nm respectively by using modified DOAS. The measurement technology parameters of SO2 have been measured within both wavebands, and the detection limits of 0.1ppm per meter and 0.6ppm per meter have been achieved corresponding to the two ranges mentioned above. By comparing the measurement technology parameters, it is obviously found that the absorption across section around 200 nm is helpful to reduce the detection limit of SO2,and this range is superior in the measurement of trace SO2.The measurement method of carbon disulfide has been researched by using broadband absorption spectrum. The detection performances of CS2 have been researched within the absorption ranges around 200 nm by using specific value method,modified DOAS and least squares method respectively. The measurement technology parameters of CS2 have been measured by using the three methods respectively, and the detection limits of 10 ppb per meter, 3ppb per meter and 3ppb per meter have been achieved corresponding to the methods mentioned above. By comparing the measurement technology parameters, it is obviously found that the modified DOAS issuperior in the measurement of trace CS2, and the least squares method will not reduce the detection performance of trace CS2.The simultaneous measurement method of the components in the compound of sulfur dioxide and carbon disulfide has been researched by using broadband absorption spectrum. The interaction effects between the two-components concentration measurements caused by the composition changing have been measured within the range around 200 nm by using the least squares method. The measuring ranges corresponding to SO2 and CS2 are 50 ppm and 10 ppm respectively. The system responds to SO2 and CS2 are 0.4 ppm and 0.02 ppm with the optical length of 20 cm by eliminating the interaction effects between the two-components concentration measurements. The minimum system responses to the concentration of SO2 and CS2 are 0.9ppm and0.03 ppm respectively with the optical length of 20 cm by overall consideration.