汞气质量浓度在线测量标定方法研究

Study on Calibration Method for On-line Measurement of Mercury Vapor

针对排放烟气中汞气质量浓度在线测量系统在标定过程中排放汞废气造成的环境污染等问题，提出了一种基于饱和蒸气原理的光谱法汞气质量浓度在线测量标定方法，并在258．65～273．55K内进行了标定实验．结果表明：在较小温差范围内，可以通过改变温度来改变饱和汞蒸气质量浓度，从而对其进行标定，经温度系数修正后可扩大标定温度区间；实验得到的标定曲线线性相关系数R2=0．9985，测得的汞气实际质量浓度与标定质量浓度的最大偏差仅为5．2％；该标定装置结构简单、成本低，且对环境无污染．

To solve the environmental pollution problems caused by waste mercury vapor emitted during the calibration of online measurement system for mercury vapor in exhaust gas, a spectrometric method based on saturated vapor principle was proposed for the calibration purpose, and subsequently corresponding cal ibration tests were performed in the temperature range of 2,58.65-273.55 K. Results show that the calibra- tion can only be performed by changing the mass concentration of mercury vapor in a small temperature range, which, however can be expanded by modifying the temperature coefficient. The linear correlation coefficient obtained by experiment is R2 =0. 998 5, and the maximum deviation between measured and call- brated mass concentra and no environmental tion is only 5. 2%. The calibration setup is featured by simple structure, low cost pollution.