What Is IFT in Transformer Oil?
IFT is measured in milliNewtons per meter (mN/m) and reflects the cleanliness and chemical stability of the oil. As polar contaminants and aging byproducts accumulate in the oil, IFT values drop—indicating the onset of oxidation, sludge formation, or contamination.
A low IFT value is an early warning sign that transformer oil is breaking down and may no longer provide proper insulation or cooling.
Test Standard
Petroleum Products – Determination of Interfacial Tension of Oil Against Water by the Ring Method
| Condition | IFT Value (mN/m) | Interpretation |
|---|---|---|
| New oil | ≥ 40 | Excellent condition |
| In-service (healthy) | ≥ 25 | Acceptable operation |
| Caution zone | 20-25 | Monitor for degradation |
| Alarm zone | < 20 | Filtration or replacement recommended |
Why IFT Testing Matters
- Detects oxidation and oil aging early
- Indicates presence of polar contaminants and surfactants
- Helps identify oil that’s losing insulating properties
- Supports preventive maintenance decisions
- Reduces risk of sludge formation and equipment failure
Our Testing Process
Sample collected in vacuum-sealed bottle with barcode ID
IFT measured using Du Noüy Ring Method in climate-controlled lab
ISO 6295 and ASTM D971 compliant instrumentation
Digital report with interpretation uploaded to ERP
AI-backed trend comparison and alerts if values drop below safe limits
Why Choose Tru-FIL for IFT Testing?
NABL-grade precision lab environment
ISO/IEC 17025:2017 compliant processes
ERP-integrated sample lifecycle and reporting
Pan-India vacuum sample collection & tracking
24/7 lab availability with AI-generated alert
Included in Your Report
- Measured IFT (mN/m) with temperature reference
- Comparison with ISO limits for oil condition
- Degradation severity (Normal / Warning / Critical)
- Maintenance recommendations (filtration / replacement)
- Historical trend chart (if available)