非色散光学法NO_2浓度测量技术研究

Technique of NO_2 Measurement by Non-Dispersive Optical Method

主要研究了一种利用非色散光学法进行N02浓度检测的技术，其基本原理是利用NO2在紫外可见光波段有较强吸收的特点，根据朗伯-比尔定律通过预先标定好的气体吸收率与浓度的关系曲线来推导气体浓度信息。在实验室使用光谱仪、氤灯和已知浓度的一系列标准样气进行实验，从光谱仪测得的290-410nm范围的光谱数据中选取带宽为5nm的四个波段，分别计算不同气体浓度下的吸收率，然后分别与浓度作多项式拟合。通过对比不同波段范围和拟合阶次下的拟合相关系数，确定了一个拟合效果最好的波段和拟合阶次，为滤光片的选择提供了依据。

A new technology of NO2 concentration measurement based on the non-dispersive optical method is studied. On the basis of intensive absorption of NO2 in the ultraviolet-visible waveband, and according to the Lambert-Beer＇s law, the concentration of NO2 can be derived by the relation curve of gas absorption rate and concentration calibrated in advance. The spectrometer, xenon lamp and a series of standard sample gas were used in the laboratory experiment. Four wavebands of 5 nm bandwidth were abstracted from the spectral data of 290-410 nm from spectrometer measurement; the absorption rates of different concentrations were calculated, and the polynomial fitting with gas concentration was made. The fitting correlation coefficients in different wavebands and fitting orders were compared, the best waveband and fitting order were obtained, and the selection basis of filter was provided.