This International Standard deals with the techniques for sampling free gases from gascollecting relays from power transformers. Three methods of sampling free gases are described.The techniques for sampling oil from oil-filled equipment such as power and instrumenttransformers, reactors, bushings, oil-filled cables and oil-filled tank-type capacitors are no longer covered by this standard, but are instead described in 4.2 of IEC 60475:2011.Before analysing the gases dissolved in oil, they are first extracted from the oil. Three basic methods are described, one using extraction by vacuum (Toepler and partial degassing), another by displacement of the dissol