油液清洁度标准及测定方法

简述了目前通用的测定油液清洁度的国际标准ISO 4406-1987（ISO 4406-1999）和美国标准NAS 1638（AS 4509）及测试方法，同时，对这些标准和测试方法的演变过程和发展趋势作了简单说明，指出从发展角度和世界范围内的应用情况看，国际标准ISO 4406将会逐渐取代美国标准AS 4509。另外，介绍了我国修改采用ISO 4406和AS 4509起草的GB／T 14039和GJB 420油液清洁度标准的情况。最后，指出国际标准和美国标准两个标准体系之间的不同之处及相互关系，说明两个标准体系采用的原理是相同的，但是对清洁度等级划分的原则不同，为此，还列出了ISO 4406和NAS 1638所测定的油液清洁度结果的对应关系，并说明了油液清洁程度和清洁度等级之间的相互关系。

STANDARDS AND TEST METHODS OF OIL CLEANLINESS

The current international standard ISO 4406 - 1987 （ISO 4406 - 1999） and American standard NAS 1638 （AS 4509） as well as test methods for oil cleanliness are introduced. And their evolution and developing tendency are explained. It is pointed out that American standard AS 4509 will be replaced by international standard ISO 4406 according to the development and application in the world. In addition, Chinese national standard GB/T 14039 and GJB 420 which modified from ISO 4406 and AS 4509 are illuminated. At last, the difference and relationship between ISO standard and American standard are shown. It is explained that they use same theory but different rule of cleanliness grade. Moreover, the correlation of oil cleanliness results determined by ISO 4406 and NAS 1638 is given and the relationship of oil clean degree and cleanliness grade is indicated.