Particle size analysis for machinery health monitoring

Abstract

MONITORING the health, or condition, of machinery is a universally accepted way of achieving economy of use and preventing catastrophic failure. Wear debris analysis is a powerful method of monitoring oil-lubricated machinery and many techniques are used, such as spectroscopic oil-analysis1, magnetic plug and filter inspection2, ferrography3, and particle size analysis. Although this last technique is frequently used for monitoring hydraulic fluids, where contamination levels are low, it has not been accepted as a means of monitoring relatively dirty systems such as gas turbines where other techniques are more efficient and easier to interpret. Here we show how the results from particle size analysis can be reduced to a simple indicator of the severity of wear; this indicator is related to spectroscopic oil analysis and shows promise as a method of monitoring the new generation of ultra-clean gas turbines.