The Rapid Method For Detecting Lubrication Based On Dielectric Properties

Lubrication is liquid lubricant used in various types of machinery to protect the mechanical parts, and is widely used in ships, vehicles, engines, compressors, and transmission components. Its main roles can be summarized five aspects as lubrication, cooling, cleaning, sealing and antisepsis. Base oil and additives are generally components of the lubrication, and the base oil is the main component that determines the basic properties of lubricant, as additives can make up for the lack performance of base oils.For the market demand of lubrication rapid detection, the principle of lubrication rapid detection based on dielectric properties is studied in depth in this thesis. A new digital capacitance sensor is designed, and lubrication rapid detector is developed based on the embedded system, and a host computer management system is designed using LabVIEW. Lubrication detection experiment is conducted to verify the practicality of the instrument.This thesis is divided into six chapters.The first chapter introduced the application and the importance of Lubrication, summarized detection method, and the importance of rapid detection was pointed out, the background, main contents and structure of this thesis were described. The second chapter studied the principle of lubrication detection based on dielectric properties, and designed the plug rod digital capacitance sensor using AD7745as the core of capacitance to digital converter, and a sensor circuit model was established to analyze the test factors. The lubrication rapid detector was developed in the third chapter, and five modules were introduced, including the instrument data processing module based on MSP430F149, man-machine interface, the temperature compensation method based on least squares curve fitting, the determine method of oil’s test results and low power design method of apparatus. The fourth chapter described the LabVlEW-based host computer system, established the communication protocol, and the host computer management system achieved oil data collection, result determination and data storage. The fifth chapter introduced the experiment to test the repeatability, resolution, temperature compensation effect of the instrument and the Host computer management system functions, and the experimental results were analyzed.Finally, this article summarizes the innovation and the shortage, and prospects the application of rapid detector, and points out the further research work.