Oil and other lubricants are essential components in rotating machinery. They can serve many purposes including:
- Reducing friction
- Transferring heat
- Moving debris and contaminants away
- Transmitting power
- Wear protection
- Preventing corrosion and rusting
- Separating moving parts
Monitoring and maintaining the lubricant can extend the life of a machine; however, contaminated lubricants can lead to premature wear and failure of machinery.
Lubricants are expensive to buy and dispose and it is necessary to monitor them for any changes. Sometimes, a perfectly functional lubricant could unnecessarily be changed out and modern testing can prevent this. Testing on lubricants can indicate the following:
- If it is still able to perform its primary function
- If it contains any contaminants
- If it has any particles that may be linked to early signs of wear of the machine components
Oil tests can measure various parameters to determine if the lubricant is still functional; these tests can measure:
- Viscosity
- Elemental concentrations
- Contamination and oil degradation
- Acid and base levels
- Water concentration levels
- Particle counts
Oil analysis can detect particles up from 6 to 10 microns in size, it can indicate if additives are being depleted, and if there are any other contaminants. The shortcomings of this method, however, include its inability to detect particles greater than 10 microns, which indicates early and/or abnormal wear. Oil analysis cannot detect the source of wear either, and it provides little information about the condition of a machine.
Oil analysis is mostly useful for monitoring the condition of the lubricant. If you would like to know more about the machine condition, then one can use wear particle analysis instead.