Abstract
The analysis of in-service lubricating fluids is a useful tool in determining the state of both the fluid and the equipment being lubricated. Many laboratories provide analysis services for in-service lubricating fluids. The results of the analyses performed are often tracked over time to allow for the observation of trends in the test results. The analysis of in-service lubricating grease is a more challenging task; since the amount of grease in many applications is quite small, the grease may be partially or totally replaced each time new grease is added, and access to the lubricated contact zone may be difficult. Many commercial in-service lubricant analysis laboratories lack the specialized test equipment required for grease analysis, so that type of analysis is performed by a limited number of laboratories, primarily those of the grease manufacturers. Various techniques are employed to determine both the macro and micro condition of in-service lubricating grease. The strengths and weaknesses of those techniques are discussed herein.
