Application of FTIR Method to Monitor the Service Condition of Used Diesel Engine Lubricant Oil

FTIR method is a common term used to monitor the lubricant oil service condition. The E2412-04 standard approved by ASTM presents a method for calculating oil condition monitoring parameters using FTIR spectroscopy. In this work, the values of ASTM parameters for 35 diesel engine oil samples were obtained to analyze the relationship between the ASTM parameters, such as the oxidation value, water content and other parameters, and the mileage of the vehicle. The driving environment of vehicle is demonstrated to be influential to lubricant oil oxidation using the ratio of oxidation rate in plateau area and in high temperature region. It is proposed that oxidation and nitration values are suitable for oil degradation analysis and oil replacement interval prediction. Further, considering the mileage, load ratio, temperature, air pressure and interference factors, the neural network of oil oxidation is constructed, and the method of oil replacement interval prediction is proposed.