Accurate measurement of trace heavy metal mercury (Hg) in flue gas of coal-fired units is great significance for ecological and environmental protection. Mixed gas was used to simulate the actual flue gas of a power plant in this study. A laser-induced breakdown spectroscopy (LIBS) system for Hg measurement in mixed gas was built to study the effect of mixed gas pressure, Hg concentration in mixed gas and delay time on Hg measurement. The experimental results show that the appropriate low mixed gas pressure can obtain high Hg signal intensity and signal to noise ratio. The Hg signal intensity and signal to noise ratio increased with the increase of Hg concentration in mixed gas. The Hg signal intensity and signal to noise ratio decreased with the increase in delay time. According to the above results, the optimized measurement conditions can be determined. Different Hg concentrations in mixed gas were quantitatively analyzed by the internal standard method and traditional calibr...

中文翻译：

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基于激光诱导击穿光谱的燃煤机组烟气中汞含量的实验研究

准确测量燃煤机组烟气中的痕量重金属汞（Hg），对生态环境保护具有重要意义。在这项研究中，混合气体被用来模拟电厂的实际烟气。为了研究混合气体压力，混合气体中的Hg浓度和延迟时间对Hg测量的影响，建立了激光诱导击穿光谱（LIBS）系统，用于测量混合气体中的Hg。实验结果表明，适当的低混合气体压力可以获得较高的汞信号强度和信噪比。汞信号强度和信噪比随混合气体中汞浓度的增加而增加。汞信号强度和信噪比随延迟时间的增加而降低。根据以上结果，可以确定最佳的测量条件。通过内标法和传统的校准方法对混合气体中不同的汞浓度进行了定量分析。