Objective Measurement uncertainty is a parameter closely related to the measurement results and is indispensable for the quality control of laboratory data. In this paper, we analyze the source of the uncertainty of sulfur dioxide emission concentration in the exhaust of fixed pollution sources, find out the various uncertainty components affecting the measurement results, and conduct the analysis and evaluation of the measurement uncertainty, so as to provide an important reference for the analysis and judgment of the accuracy of environmental monitoring data and calibrate the results. Methods The concentration of sulfur dioxide emission in fixed pollution waste gas is measured according to UV absorption method. Results The extended uncertainty of the resulting determination was 6.9%. Conclusion The uncertainty component introduced by the instrument system effect is relatively large. In addition to regular sending to the technical supervision department for verification, the user of the instrument should also carry out regular maintenance and necessary period verification to ensure the accuracy of the instrument and the repetition of the measurement.

ultraviolet absorption  /  sulfur dioxide  /  uncertainty  /  the standard method