Testing oxidation stability of elastomeres, rubber and miscellaneous plastics, such as cable coatings, is described in the German DIN 53 508 or DIN VDE 0472 as well as in IEC 811-1-2; (method: pressure chamber). This test simulates the ageing behaviour of materials in a short-term study. Materials are exposed to pure oxygen at 70℃, 21 bars or to air at 127℃ / 150℃ at 5.5 bars for one day or more in a pressure chamber. Mechanical properties, such as tensile strength and hardness, are examined before and after exposure. The results are placed in relationship to one another and the resulting characteristic number is a measure of the ageing behaviour.