What is Dissolved Gas Analysis (DGA)?

Dissolved Gas Analysis (DGA) is a diagnostic technique for assessing the condition of oil-filled electrical equipment, primarily power transformers. When a transformer develops a thermal or electrical fault, the insulating mineral oil decomposes, generating characteristic gases that dissolve in the oil. By measuring the types and concentrations of these dissolved gases, DGA can identify the nature and severity of developing faults — often months before they would be detected by other means. DGA is recognized by IEC 60599 and IEEE C57.104 as the most important diagnostic tool for transformer condition assessment.