Identify gas patterns associated with electrical and thermal activity.

What this test measures

Concentrations and relationships of diagnostic gases. It matters because identify gas patterns associated with electrical and thermal activity. the result becomes more useful when trended with a stable sampling point and corroborated by companion measurements.

Where it is used

  • Transformer oil

Scientific principle and instrumentation

Gases are extracted from oil and quantified by gas chromatography.

The typical laboratory system is a Gas chromatograph with gas extraction system. A method designation controls details such as preparation, temperature, apparatus, calibration and calculation; similar test names do not automatically produce interchangeable results.

Sample requirements and precautions

Typical requirement: 500 mL in a dedicated dry container. Confirm the complete panel before filling the bottle because particle count, volatile contamination, dissolved gases and trace-water testing may need dedicated containers.

Dissolved Gas Analysis sampling controls
ControlWhy it mattersPractical check
Representative locationAvoids stagnant or settled biasUse a consistent live-zone point where safely available
ContainerPrevents added particles, water or volatilesUse the laboratory-specified clean compatible bottle
ContextMakes the result interpretableRecord hours, top-up, fluid, maintenance and operating state

How results are interpreted

Interpretation should separate specification testing from condition monitoring. Specification work uses the exact product grade, method and decision rule. Condition monitoring emphasises comparable trends, rate of change and correlated evidence.

Dissolved Gas Analysis result interpretation
ObservationPossible interpretationCorroborating evidenceRecommended next step
Higher than baselineMay indicate a material or condition change relevant to identify gas patterns associated with electrical and thermal activity.Requires correlation with trend, companion tests and service history.Compare with baseline and rate of change
Lower than baselineMay represent normal condition, dilution, depletion or a method-specific response depending on the parameter.Do not infer acceptability without the governing specification or baseline.Review correlated tests and maintenance events
Unexpected step changeFluid, operating, sampling or analytical context may have changedTop-up, overhaul, interval, location and method recordsVerify sample identity and collection conditions

Interferences, precision and limitations

Small differences can reflect normal method precision. Compare results only when method, temperature, preparation and reporting basis are equivalent.

Common interferences

  • Non-representative sampling
  • Incorrect container or preservation
  • Matrix effects or particles outside the analytical response range
  • Method or temperature changes

Key limitations

  • Not independently diagnostic of a specific failure
  • Acceptance criteria vary by fluid, equipment, method, grade and jurisdiction
  • Copyrighted method procedures are not reproduced by the Atlas

Frequently asked questions

Can dissolved gas analysis be interpreted from one result?+

Usually not with confidence. A single result is evidence, not a complete diagnosis. Evaluate it with a comparable baseline, sampling history, operating context, companion tests and the relevant specification or OEM guidance.

What context should accompany dissolved gas analysis data?+

Asset, fluid, sampling and operating context. Record equipment and oil hours, fluid grade, make-up volume, sampling point, maintenance events, operating severity and historical results. These factors often change the meaning of the same measured value.

References and method context

References identify authoritative source families; they do not reproduce protected procedures or acceptance tables. Verify the current official edition before procedural or conformity use.

  1. IEC: IEC 60567: Oil-filled electrical equipment — sampling and analysis of free and dissolved gases