Detecting Water Content In Lubricating Oil Using Microfluidic Chip With Infrared Absorption Theory

Lubricating oil is widely used in mechanical equipment; it is a good lubricant for mechanical equipment. Water is one of the highest pollutants in the lubricating oil system; it will have a significant impact on the mechanical equipment. Therefore, in order to ensure the security and stability of mechanical equipment, lubricating oil for irregular detection is very important.In this paper, through the analysis and research the measurement of water content in lubricant, we put forward a measurement of water content in lubricating oil using microfluidic chip with infrared absorption theory aimed at the subsistent problems.In addition, we design a water content detecting system, and it realizes the concentration of water detection under laboratory conditions.The main work is as follows:(1) We put forward a measurement of water content in lubricating oil using microfluidic chip with infrared absorption theory, and the fundamental is that the infrared light has been absorbed part when through the oil detection microfluidic chip. The water content in lubricating oil can be calculated by detecting the transmitted light intensity.(2) We design a water content detecting system which upon above measurement, it mainly includes the following subsystems:oil detection microfluidic chip, optical system, electrical system and system software. The circuit of the system including the power supply module, light source drive and modulation circuit, signal amplification circuit, band-pass filter circuit, peak-detect circuit, and AD circuit. Software part of detecting system adopts Qt environment to compile software and to transplant the program to ARM development board with Linux operating system in order to realize the water concentration detection. It mainly includes infrared light source modulation process, data collection, data processing, calibrating concentration, data display and so on.(3) A series of experiments are carried to prove the effectiveness of the detection system, according to the test data, the experimental data curve, and error analysis are given. And it also finishes the concentration standardization of lubricating oil moisture detector and realizes the direct read to water concentration. The detection sensitivity of the water content detecting system which based on microfluidic chip and infrared absorption theory is500ppm, and it can meet the actual needs.