Oil inevitably degrades with use and is exposed to various sources of contamination. The benefits of oil condition monitoring can be further increased by complementing routine measurements at a centralized laboratory with more rapid on-site analysis using a portable analyzer. This article reviews infrared oil condition monitoring and describes the design considerations for an on-site oil analyzer, the In-Service Lubricants FT-IR Analysis System from 爱游戏平台注册登录 .