Corona Measurements and Their Interpretation Applied to Oil Insulated Transformers

In recent months, it has seemed that there was much confusion in the use of measurements in corona testing. On the one hand, the thought was that the charge as measured was apparent only and defied analysis. The other was that a measurement might be correlated to a dangerous level. Measurements in one case would be a discussion of detection only and not interpretation. In the other, a level might be assigned which would be satisfactory to define a safe and long life.