The Influence of Water Content on the Acid Number of Diesel Engine Lubricant in Electrochemical Measurement

Abstract

Abstract Acid Number is one of the important characteristics of lubricating oil. In this study, thick film (TF) potentiometric sensors based on ion-selective electrodes (ISE) were used to determine the acid acidity of the diesel engine oil to determine the oxidation duration of the oil. This is a real-time online detection method. Two working electrodes (polymer electrode and glass electrode) and a reference electrode (bare Ag electrode) were fabricated, and the acid acidity of the diesel engine lubricant was expressed in the form of voltage, which overcomes the insufficiency of the titration endpoint in the titration method. Among oil products, most varieties only allow traces (water content below 0.3%) of moisture, and some oil products do not allow moisture. Water in oil can emulsify diesel engine lubricant, decompose additives, promote the oxidation of oil products. It affects the low-temperature fluidity of oil products. For transformer oil, extremely small amounts of water will seriously affect its insulation performance. In the experiment, the influences of water content for the acid acidity of the diesel engine lubricant were considered and tested.