What does the PPM test measure in transformer oil?

The PPM test in transformer oil measures the concentration of dissolved gases, specifically parts per million (PPM) of gases like hydrogen, methane, ethane, and others. This analysis is crucial for assessing the condition of the transformer, as elevated gas levels can indicate insulation breakdown or overheating. Regular PPM testing helps in predictive maintenance, allowing for timely interventions to prevent transformer failures and extend operational lifespan.