DIN EN ISO 4263-3:2011-02

This document contains the German translation of the international document ISO 4263-3:2010, which has been prepared by Technical Committee ISO/TC 28 "Petroleum products and lubricants", the secretariat of which is held by ANSI (USA), in collaboration with Technical Committee CEN/TC 19 "Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin". The responsible national committee is NA 062-06-81 AA, Mirror Committee of CEN/TC 19 "Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin" of the Petroleum, Fuels, Lubricants and Related Products Standardization Committee (NMP). This part of ISO 4263 specifies a method for the determination of the ageing behaviour of anhydrous synthetic hydraulic fluids of categories HFDR, HFDU, HEES and HEPG as defined in ISO 12922 and ISO 15380. The ageing is accelerated by the presence of oxygen, water and metal catalysts at elevated temperature, and the degradation of the fluid is followed by changes in acid number. Other parts of ISO 4263 specify similar procedures for the determination of ageing behaviour of mineral oils and specified categories of fire-resistant fluids and synthetic fluids used in hydraulic and other applications. This test method can be used to compare the oxidation stability of hydraulic fluids that are not prone to contamination with water. Because of the large number of individual field-service applications, a correlation between the results of this test method and actual service performance of the oil can vary and only be proved during operation. The precision for this test method is not known because interlaboratory data are not available. That is why this test method might not be suitable for use in specifications or in the event of dispute as long as these data are not available. However, precision for turbine oils is given for guidance as it could be also obtained for synthetic hydraulic fluids.