对非分散红外SO2 气体检测技术及其运行机理作了系统介绍。分析了非分散红外 SO2 气体检测的吸光度获取方案及浓度反演方法。以三阶多项式为拟合模型，采用非线性最小二乘法获得了系 统的定标曲线。对系统的测量准确度进行了相关分析，得出测量误差< 2 %。结果表明，利用非分散红外光谱吸收法能 够实现对SO2 气体的准确测量，可为其它气体的测量提供相似的解决方案。

The non-dispersive infrared gas analysis technique and its application in sulfur dioxide measurement are presented. The absorbance acquisition and concentration retrieval in non-dispersion sulfur dioxide analysis are analyzed. By taking the third-order polynomial as a fitting model, the calibration curve is obtained with the nonlinear least-square. The measurement accuracy of the system is analyzed and the measurement error less than 2 % is derived. The result shows that the non-dispersive infrared technique can measure the sulfur dioxide accurately and it can also be used in the analysis of other gases.