How does a transformer oil degasser remove dissolved gases?

A degasser removes dissolved gases by exposing oil to vacuum and increased surface area, allowing gases to escape at lower pressure. Under vacuum, gases such as hydrogen, methane, and oxygen are released from the oil and extracted. This improves dielectric strength and reduces the risk of partial discharge. Degassing is often combined with dehydration because moisture and gases interact. Controlled degassing preserves diagnostic gas trends by avoiding excessive removal that could mask active fault conditions.