Wear Modes identification by Ferrography and Laser Net Fines

One of the most common questions asked when discussing a red actionable report with a client, is “can you tell me more how this happened.” When there are obvious contamination sources such as dirt, water or the wrong oil in use then this is easily spotted on the oil analysis reports. However, sometimes, the flag may just be one wear metal increasing – such as iron, which is the most common element found in lots of components. This makes identifying the source of the iron wear difficult and often further lab or field testing analysis is required to investigate the cause. One additional investigation that is possible is analysis of the wear type on actionable high particle count or wear reports. This can be included in your test suite as standard to perform on all actionable reports if required – just ask the lab for more details. This is performed by a technique called Laser-Net Fines where the particle counter analyses not only by laser to determine ISO code, but an optical camera also scans the flow of fluid at the same time and uses image recognition software to identify larger (>20µm) particles and the wear type occurring. A contour of each of the particles identified is then placed on the report and categorised into its particle type. The overall percentage of each wear type is tabulated, together with the percentage of the abnormally sized particles identified compared to the smaller particles to identify the significance of the particles detected to provide a holistic view of the overall equipment condition.

word image 36 Wear Modes identification by Ferrography and Laser Net Fines

Abnormal Size – This test as part of the LearnOilAnalysis LNF report identifing what percentage of the particles analysed are abnormally sized. A low value suggests that although a few larger particles are present the majority of the particles are of a normal size and the wear levels should just be monitored for any increasing trend in abnormal size, PQ or wear metal values. A high value suggests the particles are predominantly large particles suggesting (if the sample is representative of the bulk of the system) that there is an abnormal wear mechanism developing in the system and this should be investigated further.

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