What is the neutralization number of transformer oil?

The neutralization number of transformer oil, also known as the acid number, measures the amount of acidic substances present in the oil. It is typically expressed in milligrams of potassium hydroxide (KOH) per gram of oil. For high-quality transformer oil, the neutralization number should generally be less than 0.03 mg KOH/g. Regular monitoring of this parameter is essential to assess the oil’s condition and prevent degradation of the transformer insulation system.