The backbone test of oil analysis, usually inductively coupled plasma (ICP) or rotating disc electrode (RDE) spectroscopy, reporting around 20 elements in ppm. Iron, copper, lead, tin, chromium and aluminum point to wear of specific parts; silicon, sodium and potassium point to dirt, coolant or process ingress; zinc, phosphorus, calcium and molybdenum fingerprint the additive package. It only sees particles up to a few microns across.
Elemental analysis shows silicon at 45 ppm with aluminum tracking it, that's dirt, not sealant.
Silicon and aluminum rising together, with silicon several times higher, is the fingerprint of dust; silicon alone is often just sealant or antifoam additive.
Also heard as
- spectrometric analysis
- spectro
- ICP
- wear metals
Related terms
Oil analysis
Lab testing of in-service oil samples to judge oil condition, contamination and machine wear.
PQ index
Magnetic measure of total ferrous debris in an oil sample, including large particles that spectrometers miss.
Additive package
Pre-blended mix of performance chemicals that a blender adds to base oil to make a finished lubricant.
Analytical ferrography
Microscope study of wear particles pulled from oil by a magnet, used to identify how a machine is wearing.