AN investigation of the accelerated oxidation method for predicting the gum stability of gasolines was made to determine the effects of oxygen pressure and of temperature on the observed induction periods. The data obtained on the effect of pressure indicated that there was a definite relation between the induction period at any pressure and the induction period at an air pressure of 1 atmosphere. The data obtained on the effect of temperature showed that the induction periods of different gasolines changed to a different extent with temperature, so that gasolines with the same induction period at any one temperature might have very different periods of stability at storage temperatures.
Since temperature has a marked effect on the observed induction period and since the gasoline is at a lower temperature than that of the bath for a considerable period of time at the beginning of the experiment, a correction factor was applied to obtain true induction periods at the bath temperature. A method is suggested for predicting the length of time for which a gasoline can be stored without excessive gum formation. However, the values obtained are only approximate and further work is necessary to test the validity of the prediction.
Some major subjects of discussion are whether it is necessary to measure the induction period at two different temperatures, how long gasoline can remain in the fuel system befoire resin is formed and definitions of gum and of resin.