【摘要】 差分吸收光谱法（DOAS）应用于固定污染源烟气排放监测时,烟气温度及气体的非线性吸收对准确测量气体浓度影响较大,必须对温度及非线性吸收的影响进行修正。文中分别提出了新的温度补偿及新的非线性补偿方法,即将不同温度下气体的分子数密度与20℃下气体的分子数密度之比与温度的对应关系拟合出温度补偿函数,将气体实际浓度所对应的分子数密度与反演结果所对应的分子数密度之比与反演结果之间的对应关系拟合成非线性补偿函数,利用这两个补偿函数对浓度反演结果进行补偿。对14914mg/m³的SO₂气体在70～170℃温度范围内的实验研究结果表明,新的温度补偿及非线性补偿函数能很好的补偿温度及非线性的影响,具有较高的气体浓度反演精度。更多还原

【Abstract】 The effect of temperature and nonlinear absorption to correct concentration measurement of polluted gas is obvious when the Differential Optical Absorption Spectroscopy(DOAS)technique is applied to monitor the flue gas from f(?)xed pollution source.So we should take the temperature and nonlinear absorption effect into account.New temperature and nonlinear compensation methods are proposed respectively.The relationship of the ratio between the molecular density of flue gas at different temperatures and that at 20℃with temperature is fitted as a temperature compensation function,and the relationship of the ratio between molecular number density corresponding to real concentration and that corresponding to the measurement result with the retrieved concentration is fitted as a non-linear compensation function.These two fitted functions are used to compensate for the temperature and nonlinear absorption of the retrieved concentrations.Experimental results for SO2 with concentration of 14 914 mg/m~3 and temperature range of 70～170℃show that the measurement results are well compensated with higher precision using this method.更多还原