I work in a chemical laboratory and test transformer oil – oil testing requires physical-chemical and electrical tests, which include: determination of water content by Karl-Fischer titration, measurement of breakdown voltage, measurement of tanδ and specific resistance of oil, determination of neutralization number, determination of surface tension, determination of inhibitor content by FTIR. I also examine the content of gases dissolved in oil using a gas chromatograph with head space, I also determine 2-furfural by HPLC method, determine corrosive sulfur and examine the remaining life of transformer oil (oxidative stability of the oil).