WMS的玻璃药瓶内氧气含量检测及其标定方法改进

摘要

应用激光波长调制光谱(WMS)技术,建立了一种开放光路短光程检测玻璃药瓶内氧气含量的方法.选择氧气分子位于760.885(13142.58 cm-1)的吸收谱线,通过多次调试优化了系统相关参数,给出了实时扣背景及实时谱线校正等数据处理的方法和步骤.采集七种不同氧气含量的玻璃药瓶样本,获取相应的二次谐波信号,分别建立二次谐波峰值、半高谱峰面积与浓度的线性回归方程进行定量预测.实验结果表明,其拟合系数分别为0.9966和0.9978,后者相比前者的标定方法提高了0.12%.采用完全交互验证的方法来评价两个模型的预测精度,其预测的均方根误差(RMSEP)分别是0.0031和0.0020,后者相比前者降低了37.69%.对浓度是4%的气体样品,比较不同时间的20次测量结果,标准差分别为0.0022和0.0016,后者相比前者降低了27.3%,同时其测量灵敏度分别为0.198%和0.097%,后者相比前者的灵敏度提高了约51%.证明了该系统及数据处理方法对玻璃药瓶内氧气含量检测是可行的,且利用半高谱峰面积更丰富的幅值信息来反演气体浓度可以降低波峰失真影响,检测精度更高,稳定性更好.%Pharmaceutical vial's oxygen concentration detection based on wavelength modulation spectroscopy (WMS)was con-ducted on a single,short optical path in the open.The oxygen absorption lines at 760.885 nm (13142.58 cm-1 )were chosen-and the system parameters were optimized.Then,data processing method and steps were explained,such as real-time back-ground deduction and real-time spectrum correction.Seven samples of the different oxygen concentrations were tested,and the corresponding second harmonic signals were obtained.Finally,the linear regression equations were established between the con-centration and the peak height(C—H),the peak area at half maximum(C—A).The experimental results indicated that the fit-ting coefficients of two methods were 0.9966 and 0.9978,respectively,and the latter was increased by 0.12 % than the for-mer.Prediction accuracy of the model was evaluated by fully interactive authentication method and the results indicated that the root mean square errors of prediction (RMSEP)were 0.0031 and 0.0020,respectively,and the latter was reduced by 37.69%than the former.The 2f signal of sample (4%)were severally measured for 20 times by the two methods in different time and the results indicated that standard deviations were 0.0022 and 0.0016,respectively,and the latter was reduced by 27.3% than the former.Meanwhile,the resolutions were 0.198% and 0.097%,respectively,and the latter was increased by 51% than the former.The system is feasible to measure the pharmaceutical vial's oxygen concentration,and the accuracy and stability of the system can be improved by the C—A method.