基于反射光谱技术原理研究润滑油的污染浓度预测模型。 选用纯净润滑油和原态污染油为原料, 采用等体积法逐一配置不同浓度的样本； 调整好光纤探头与样品之间的距离及方位角并保持不变, 采用脉冲氙灯为激发光源, 利用波段在200~850 nm范围的光谱仪对不同浓度的样本进行反射光谱测量实验。 实验曲线观察分析表明, 润滑油的污染浓度越高, 反射光谱的强度越低。 在采用变步长算法对原始实验数据进行稀疏采样的基础上, 分别采用相关系数法、 主成分分析法、 主成分分析结合相关系数法(主成分-相关系数法)选取工作润滑油在220~780 nm宽波段范围内的优势特征波长, 并在所选取的优势波长处建立了润滑油污染浓度与光谱反射率的指数关系模型。 测试结果表明, 主成分-相关系数法选取的优势波长37893 nm, 所建立的污染浓度与光谱反射率的指数回归模型能够较好地实现润滑油污染浓度大于006时的预测和估计。 基于主成分-相关系数法选取优势特征波长所建立的指数关系回归模型, 因混合介质及浓度的特异性条件, 不服从低浓度均匀透明溶液中的朗伯-比尔定律, 适用于较高污染浓度的润滑油质量状态估计, 为进一步实现工作润滑油污染浓度的反射光谱法在线快速准确测定提供了可行性实验依据。

The pollution concentration prediction model of lubricants based on the principle of reflection spectrum is studied. Pure oil and full pollution oil are chosen as experimental materials. Different concentration samples are gradually prepared by equivalent volume method. The spectrometer of 200~850 nm band range is used to measure the samples. Xenon lamp serves as excitation light source. After adjusting, remain unchanged the distance and geometry azimuth between the detector probe and the sample, spectral measurement can be just conducted. The spectral reflectance experimental results show the higher contamination of the lubricants, the lower intensity of the reflected spectrum. In the variable step size algorithm on the original experimental data sparse sampling based, Correlation Coefficient, PCA, and PCA combined with Correlation Coefficient method (PCA-Correlation Coefficient) are respectively adopted to select advantage characteristic wavelength of lubricating oil in the wide band of 220~780 nm, and the index regression model is established about oil pollution concentration and spectral reflectance. Test results show that when the concentration is greater than 006, the index regression model of pollution concentration and spectral reflectance at 37893 nm which is selected by PCA-Correlation Coefficient can well realize the prediction and estimation of pollution concentration of lubricant oil. So the regression model based on PCA-Correlation Coefficient to select advantage wavelength is suitable for the quality estimation of lubricating oil with high pollution concentration. Because of the specific conditions of the concentration and mixed medium, the model does not obey Lambert-Beer Law, which apply to low concentration, uniform and transparent solution. The paper provides a feasible experimental basis for the further to achieve the working lubricants pollution concentration with reflection spectrum method online, fast and accurate determination.