Transformer oil analysis provide vital information on the state of the transformer and its internal condition. It can detect various internal faults such as partial discharge, overheating, hot-spots, sparks and arcs and the general state of the insulation.
One of the most important oil test is the Dissolved Gas Analysis check (DGA). It is the only oil test that can detect a wide range of transformer internal faults.
A suite of basic oil tests include breakdown voltage test (BDV), acidity, interfacial, visual, moisture test and power factor. They all can point to a presence of a problem in the transformer.
An advanced test is the furan level test, which can indicate the remaining life of the transformer.