The principle of the method specified is oxidizing the sample in a pressure bomb initially filled at 15 °C to 25 °C with oxygen at 690 kPa, heating at a temperature between 98 °C and 102 °C, reading the pressure at stated intervals or recorded continuously until the breakpoint is reached. The time required for the sample to reach this point is the observed induction period at the temperature of test, from which the induction period at 100 °C may be calculated. The method is applicable for aviation and motor gasolines in their finished form only.