The Usefulness of Particle Counting in Oil Analysis

By Jim Fitch
Electric Power Research Institute (EPRI) NMAC Lube Notes

Optical particle counters (OPC’s) have a long history of use in industrial hydraulic applications. Traditionally, their success has been limited to scientific laboratories and other highly controlled environments. However, in recent years, attempts have been made to apply the use of OPC’s to the particle counting of used hydraulic fluids and industrial lubricants. As a result, serious concerns have been raised regarding the accuracy and reliability of OPC’s in such applications. The objective of this bulletin is to present important facts from reliable and documented sources for the general benefit of existing or prospective users of OPC’s. As particle counting moves into the mainstream of machine condition monitoring, users must have reliable information to identify and select appropriate technologies.