Oil analysis is able to monitor the health of the lubricant, the health of the machine and levels of contamination through a series of chemical and physical tests. However, it is a snapshot in time of these three parameters. It lets you know what was going on at the time the sample was taken – sometimes more information is required.
Oil filters contain wear and contamination debris that has built up over time, it is like a diary of what has happened to the component since the filter was last changed. The filter can contain debris that is too large to circulate in the oil and would not necessarily show up in traditional oil analysis. It is also effective where large sump volumes may mean that wear and debris are too diluted to be detected at useful levels.
Filter analysis involves the removal of a small amount of the filter medium. This is then agitated with special solvents to remove the debris, the solvent is then filtered through a membrane and examined under a microscope. Basic metal types such as iron, copper, white metal and aluminium are identified and quantified. The same analysis is performed on contaminants such as dirt, rust, carbon grit and oil residues.
The mass of the debris and its PQI is also measured. A photograph is taken of any relevant debris, a subjective description of the debris is made and, where possible, a cause is suggested and corrective action is made. This all contained in printed or electronic format.