Evaluation and analysis of uncertainty in measurement of SO2 automatic monitor

In this paper, uncertainty in measuring SO
₂
concentration based on ultraviolet fluorescence method is analyzed and evaluated according to normalized require and related data in< Evaluation and Expression of Uncertainty in Measurement>. The results indicate that measurement uncertainty mainly originates from the indicating value uncertainty of the apparatus, concentration definite value uncertainty of calibrating gas and the uncertainty indicated by ambient temperature variation and supply voltage fluctuation.