Abstract :
It is known that insulating oils may give off gas, chiefly hydrogen, under the influence of an electric discharge. This generation of gas is particularly marked in the case of oils which have been exhaustively refined to make them more resistant to oxidation. In this paper an attempt is made to discover to what extent the generation of gas of refined oils can be suppressed by the addition of relatively small quantities of aromatics. Insulating oils always have a more or less extensive boiling range. If it be desired to have a slight tendency to generate gas, with a relatively small percentage of aromatics, it is important that the aromatics present should be of the lowest boiling constituents.
