Determination of wear metals in used lubricating oils by X-ray fluorescence spectrometry

Application of an X-ray fluorescence analytical procedure for the determination of wear metals in used lubricating oils is described. Oil samples were collected from UH-1H type helicopter engines at regular intervals and subjected to chemical pretreatment in order to remove the high viscosity of the oil and particle size effects. The procedure was used to determine the concentration of copper and iron wear metals in oils. They were found to increase with engine operating time. The results obtained show that the XRFS procedure provides a better indication of impending machine failure than conventional methods.