采用组合区间偏最小二乘法结合红外光谱法快速测定在用润滑油的运动粘度.采用组合区间偏最小二乘法高效提取与粘度变化相关的光谱信息,提高粘度校正模型的测量精度.在设置4 000~400 cm-1范围的区间数为12时,选择2,10,11,12等4个子区间,对应的光谱区域为1 300~400 cm-1、3 700~3 400 cm-1,模型校正偏差达到0.031 5.对模型预测精度的验证结果说明本法与运动粘度标准方法之间具有很好的相关性,模型可以用于定量分析在用润滑油在40 ℃时运动粘度值.

BiPLS combined with IR was used for the rapid determination of dynamic viscosity in used lubricating oil.In order to improve the measurement accuracy of the viscosity calibration model,backward interval partial least squares (BiPLS) algorithm were applied to the efficient extraction of spectral information on viscosity changes.The spectrum with wavenumber from 4 000 cm-1 to 400 cm-1 was divided into 12 intervals.With the 4 subintervals of 2,10,11,12,the corresponding wavenumber ranges of 1 300-400 cm-1 and 3 700-3 400 cm-1 were selected.The standard error of calibration model found was 0.031 5.According to the verification result of the predicted accuracy of model,the method had good correlation with the standard method for dynamic viscosity.The model could be used for quantitative analysis of values of dynamic viscosity of used lubricating oil at 40 ℃.