Oil analysis is a powerful technique used to monitor the health and condition of motor lubricants in machinery and engines. It involves the systematic analysis of the lubricating oil to detect and quantify various factors such as wear particles, contaminants, and degradation products. This information helps maintenance professionals assess the condition of the equipment and make informed decisions about when to change the oil or perform maintenance. Here's how oil analysis identifies these different aspects:
Wear Particles:
Wear particles are generated as a result of mechanical friction and abrasion between moving parts within an engine or machinery.
Oil analysis involves passing a sample of the lubricating oil through a filter or membrane, which captures suspended particles.
The captured particles are then examined under a microscope or analyzed using specialized techniques such as Ferrography or Optical Particle Counting (OPC).
These techniques allow experts to classify and quantify the type and size of wear particles present, indicating which components might be experiencing abnormal wear or deterioration.
Contaminants:
Contaminants in motor lubricants can come from external sources (such as dust, dirt, water, or fuel) or internal sources (degradation of oil additives or engine components).
Various analytical methods are used to identify and quantify contaminants. For instance:
Infrared (IR) spectroscopy can detect the presence of water, fuel, and certain degradation products.
Atomic emission spectroscopy or inductively coupled plasma (ICP) can determine the concentration of metal contaminants, such as iron, copper, and aluminum, which may indicate wear or corrosion.
Gravimetric methods can be used to measure the total amount of solid contaminants in the oil.
Filter patch analysis involves capturing contaminants on a membrane filter for visual inspection or further analysis.
Degradation:
Over time and under operating conditions, lubricating oils undergo chemical changes and degradation.
Oil analysis monitors the degradation of the oil by examining changes in its physical and chemical properties.
Techniques like viscosity measurement, Fourier-transform infrared (FTIR) spectroscopy, and acid number determination can provide insights into the oil's degradation level, oxidation, and acid content.
A rise in viscosity or the presence of oxidation products can indicate that the oil's useful life is nearing its end.
Oil analysis is typically performed at regular intervals, and the data collected over time are used to establish trends and deviations from the norm. This allows maintenance professionals to make informed decisions about oil changes, equipment servicing, and potential issues that might arise in the machinery or engine. By proactively addressing wear, contaminants, and degradation, oil analysis contributes to extending equipment life, reducing downtime, and optimizing maintenance practices.