• Method adopted/last revised: 2008
• Method reapproved: None
• REF/ISBN: IP560-2936450
• Status: Current
• First printed in STM books: January 2008

Scope

This Standard specifies a procedure for the determination of the silicon, nickel, chromium, iron and copper content of used lubricating greases by wavelength dispersive X-ray fluorescence spectrometry. The concentration ranges that this method covers are:

Element        Range mg/kg

Silicon            1 to 220
Nickel             1 to 220
Chromium      1 to 180
Iron                10 to 3500
Copper           1 to 155

NOTE 1 - This standard is suitable for the condition monitoring of machinery by the analysis of the wear metals in the lubricating grease. This standard is designed for trend analysis of the elements listed. The precision shown for each element obtained from a round robin study is supplied to provide indicative performance on repeatability and reproducibility. Due to the inhomogeneous nature of the samples a high variance can be expected thus individual measurements should not be used in isolation but as a measure of trend.

NOTE 2 - Results obtained from ICP-OES determinations of the same round robin samples indicated that XRF measurements produced higher results for all elements except Fe where the results were comparable.