Age detection of lubricating oil with on-line sensors

Lubricating oil as the blood of machine carries profound information of the life-span performances. Naturally, oil degrades with serving time and cause severe wear. Therefore, it is very important to detect the age of lubricating oil, which can reveal lubrication conditions and wear conditions as well. To characterize oil performances quantitatively, the physical and chemical properties are monitored with an on-line oil property sensor focusing on viscosity and permittivity. Moreover, an online wear debris sensor is adopted to detect the wear along with oil deterioration. With these on-line sensors, an aging process of oil and the consequence of wear can be informatively understood. Experimentally, an oil aging test is carried out in a four-ball test rig with on-line sensors of oil properties and wear particles. Results show that the aging process of lubricating oil, which is comprehensive and uninvestigated, can be monitored with online sensors, and the accuracy for the detection is verified with off-line analysis.