Testing Oil Cleanliness Using SEM

Lubricating oil is used to separate surfaces, in order to reduce the friction between the surfaces and to absorb heat caused by the friction. In order to keep the surfaces well lubricated, the oil needs to be the proper type and uncontaminated, with the machinery in good working order and well maintained. Otherwise, if the oil is contaminated, the metal-to-metal or particle-to-metal contact causes the surface to wear, which generates more friction, more heat, and more wear particles in the oil.

Oil contaminates, whether dirt, moisture, metal fragments or other foreign particles, can be identified in order to minimize the impact these particles have on the workings of the machinery. Identifying the source can also help in the oil analysis to see if the oil properties are intact and if the machinery has any wear occurring.

The International Organization for Standardization (ISO) 4406 provides a universal method to report the contamination levels in oils by establishing the relationship between particle count and cleanliness. Using the ISO 4406, limits can be set for acceptable contamination levels based on the particle size in micrometers (µm). In order to size the particles and assess contamination levels, Aspex has created a software platform for its Personal Scanning Electron Microscope (PSEM) called Advanced Quality Control (AQC).

The AQC software, in conjunction with the PSEM, allows manufacturers and machinists to be able to quickly and accurately analyze the particles of oil in order to see what contaminates, if any, are present. This totally integrated solution for the automated detection, identification, and characterization of micron-level debris in automotive manufacturing that can be utilized directly on the manufacturing floor.

By using the AQC to identify and classify the particles found in the oil and using the ISO 4406, manufacturers and machinists have necessary information to examine where the particles are originating. If possible, the oil contaminate source can be eliminated, or at least minimized, once the particles are identified and the elemental composition known.

Oil cleanliness is a high standard to meet, as some particles cannot be prevented from being incorporated into the oil. Taking preventative steps can help save costly downtime in the future due to unusual wear on the machine’s parts, and can aid in extending the life of the machine. The Aspex PSEM with AQC is the ideal tool for identification and sizing of foreign particles in order to meet with the standards of cleanliness required by manufacturers and consumers alike.

Reference:
Aspex, http://www.aspexcorp.com/industries/industrial-automation.html
Noria, http://www.noria.com/learning_center/category_article.asp?articleid=738&relatedbookgroup=OilAnalysis
Bently, http://www.bentlytribology.com/publications/articles/1199white.php
MRT Labs, http://mrtlaboratories.com/iso4406chart.htm