What Is Buchholz Gas Analysis?
Buchholz Gas Analysis is the process of collecting, identifying, and quantifying the gases that accumulate in the Buchholz relay. The test helps detect early-stage faults inside the transformer — even before conventional alarms or oil breakdown symptoms occur.
Each gas produced inside the transformer correlates with a specific type of fault. By identifying the gas composition, engineers can determine whether the cause is thermal, electrical, or due to insulation degradation.
Test Standard
- Gas is extracted from the Buchholz relay using sealed vacuum-tight collection equipment
- Volume, color, and odor of gas are recorded for initial assessment
- Gas is transferred into gas-tight syringes or vials for laboratory testing
- Analysis is performed via Gas Chromatography (GC), providing accurate gas concentration (ppm)
Key Gases Measured
Insulating Liquids – Measurement of Relative Permittivity, Dissipation Factor (Tan δ) and DC Resistivity.
| Gas | Indicates |
|---|---|
| Hydrogen (H₂) | Partial discharge, corona |
| Methane (CH₄) | Low-temperature overheating |
| Ethylene (C₂H₄) | Medium-temperature overheating |
| Acetylene (C₂H₂) | High-energy arcing faults |
| Carbon Monoxide (CO) | Paper insulation breakdown |
| Carbon Dioxide (CO₂) | Aging of insulation paper |
| Oxygen (O₂) | Oil degradation or air ingress |
| Nitrogen (N₂) | Internal pressure or air ingress |
Diagnostic Insights
- Minor overheating
- High-energy arcing
- Insulation decomposition
- Air ingress or oil contamination
When Should You Request a Buchholz Gas Analysis?
- After a Buchholz relay trip or alarm
- As part of periodic condition monitoring
- During scheduled shutdowns or oil testing
- Prior to re-energizing after maintenance
Report Includes
- Gas volume extracted (mL)
- Gas composition (ppm for each hydrocarbon gas)
- Fault diagnosis based on gas signature
- Severity classification (normal / warning / critical)
- Maintenance recommendation (monitor / service / shut down)
Why Choose Tru-FIL?
- Expertise in transformer gas diagnostics
- Field engineers equipped with portable gas extraction tools
- NABL-grade laboratory and GC instrumentation
- AI-powered ERP for historical fault tracking
- Trusted by leading utilities, OEMs, and service providers