Standard Test Method for Determination of the Oxidation of Used Lubricants by FT-IR Using Peak Area Increase Calculation
Get more information about the standard at ASTM D2879-23.
ASTM D7214 is a standard test method for the determination of oxidation in used lubricants by Fourier Transform Infrared (FT-IR) spectroscopy using peak area increase calculation. Oxidation is a key indicator of lubricant degradation, which affects the performance and longevity of engines and mechanical systems. This method provides a reliable means to monitor oxidative changes in lubricants during service, helping to ensure operational efficiency and prevent equipment failure. ASTM D7214 plays a critical role in condition monitoring and predictive maintenance in automotive, industrial, and laboratory settings.
Details
The test method outlined in ASTM D7214 measures the increase in absorbance in the carbonyl region (typically around 1600–1800 cm⁻¹) of the FT-IR spectrum, which correlates with oxidation products such as ketones, aldehydes, and carboxylic acids. These compounds are formed as the lubricant oxidizes over time under thermal and mechanical stress.
The procedure involves comparing the FT-IR spectrum of a used lubricant sample against that of a baseline (fresh or minimally degraded oil). The peak area increase (PAI) is calculated to quantify the extent of oxidation. This method is especially useful for analyzing in-service transmission fluids but may be applicable to other lubricants as well, although precision may vary.
Interference from additives or contaminants that absorb in the same spectral region may affect the accuracy of the results. Therefore, the method is best used for trend analysis rather than absolute quantification.
Industries & Applications
ASTM D7214 is widely used in industries where lubricant condition monitoring is essential:
- Automotive and heavy machinery: Enables early detection of oil degradation, supporting preventive maintenance and reducing downtime
- Lubricant formulation and testing: Assists in evaluating oxidative stability and performance of lubricant additives
- Industrial equipment maintenance: Provides ongoing assessment of lubricant health in hydraulic systems, gearboxes, and transmissions
- Laboratory research: Used to study oxidation behavior under controlled test conditions or in accelerated oxidation testing