What Is Oxidation Stability?
Oxidation stability refers to the oil’s resistance to chemical breakdown when exposed to heat, oxygen, and metal catalysts. The test simulates accelerated aging in the laboratory to evaluate the rate of acid and sludge formation. This helps predict the oil’s service life and its ability to protect transformer components over time.
Test Standard
IEC 61125 – Insulating Liquids – Test Method for Oxidation Stability
Test Procedure Summary
Oil is aged in a sealed vessel with copper/iron catalyst coils at 120°C
Dry air is passed through the oil for 164 hours (Method C) or 500 hours (Method A)
After aging, the oil is tested for acidity, sludge content, interfacial tension, and dielectric strength
Results indicate oil’s oxidation resistance and remaining life
Key Gases Measured
Insulating Liquids – Measurement of Relative Permittivity, Dissipation Factor (Tan δ) and DC Resistivity.
| Result | Interpretation | Action Required |
|---|---|---|
| Corrosive | Reactive sulphur detected | Immediate action: filtration or replacement |
| 100Non-Corrosive | No reactive sulphur present | Oil safe for use |
Why Oxidation Stability Testing Is Important
- Predicts long-term oil performance and life expectancy
- Identifies oils that degrade rapidly under heat and air
- Assesses effectiveness of antioxidants (e.g., DBPC)
- Helps choose the right oil for new or refurbished transformers
- Supports preventive maintenance and oil replacement decisions
Our Testing Process
- Vacuum bottle sample collection with barcode tracking
- Sealed aging under oxygen-rich environment in lab reactors
- Post-aging analysis of acidity, sludge, and other parameters
- IEC 61125-compliant instrumentation and procedures
- ERP-integrated results with AI-based life expectancy estimates
Report Includes
- Oxidation stability classification (Pass/Fail)
- Post-aging acidity, sludge %, interfacial tension
- Suitability for continued service or oil replacement
- Trend comparison (if historical data available)
- Expert recommendations based on IEC guidelines
Why Choose Tru-FIL?
- IEC 61125-compliant laboratory with precision testing setups
- NABL-grade facilities and experienced chemists
- AI-powered ERP for tracking and interpretation
- Nationwide vacuum-based sample pickup
- 24/7 laboratory operations and digital reporting