Development of a New Lubricant Degradation Monitoring Technique Using Terahertz Electromagnetic Waves

Abstract

Condition monitoring of lubricating oil is an effective method for early detection of abnormalities in rotating machinery in plants. In this research, a new monitoring technique for lubricant degradation using terahertz waves, which are electromagnetic waves located in the boundary region between light and radio waves, is developed based on the correlation between lubricant degradation and the transmission characteristics of terahertz waves. It is found that there is a correlation between the transmission characteristics of terahertz waves, such as transmittance and refractive index, and typical lubricant degradation, such as base oil degradation, water contamination, and metallic wear debris contamination. The results suggest that a new lubricant degradation monitoring technique using terahertz waves is possible by using these transmission characteristics.

Keywords

• terahertz electromagnetic waves
• lubricating oil
• degradation monitoring