Oxidation - Lubricating Oil Analysis
Lubricating oil in engines and other components combines with available oxygen under certain conditions to form harmful by-products. Heat, pressure, and catalyst materials accelerate the oxidation process. By-products of oxidation form lacquer deposits, corrode metal parts, and thicken oil beyond its ability to lubricate. Most lubricants contain additives that inhibit or retard the oxidation process.
Differential infrared analysis offers the only direct means of measuring the level of oxidation in oil. Note: A new oil reference is required for accurate measurement of oxidation. Results are reported on an absorbance scale.
Cause
• Overheating
• Extended oil drain interval
• Improper oil type/inhibitor additives
• Combustion by-products/blow-by
Effect
• Shortened equipment life
• Lacquer deposits
• Oil filter plugging
• Increased oil viscosity
• Corrosion of metal parts
• Increased operating costs
• Increased overall wear
• Decreased engine performance
Solution
• Use oil with oxidation inhibitor additives
• Shorten oil drain intervals
• Check operating temperature
• Evaluate equipment use vs. design
• Evaluate operating conditions
