绝缘液体.粒子计数和大小测定用方法

[中文适用范围]： 本标准描述了测定颗粒浓度和粒径分布的取样程序和方法。指定了三种方法。一种使用自动粒度分析仪，根据光中断原理工作。另外两种使用光学显微镜，在透射光或入射光模式下，对膜过滤器表面收集的颗粒进行计数。光学显微镜方法是ISO 4407 中描述。所有三种方法均适用于已使用和未使用的绝缘液体。附件 A 包含使用注射器的替代采样程序，附件 B 报告了自动粒子计数器校准的参考。 [外文原描述]： Describes the sampling procedures and methods for the determination of particle concentration and size distribution. Three methods are specified. One uses an automatic particle size analyser, working on the light interruption principle. The other two use an optical microscope, in either the transmitted light or incident light mode, to count particles collected on the surface of a membrane filter. The optical microscope methods are described in ISO 4407. All three methods are applicable to both used and unused insulating liquids. Annex A contains an alternative sampling procedure using a syringe and Annex B reports a reference for the calibration of automatic particle counters. The significant technical changes with respect to the previous edition are as follows: - new calibration procedures for automated laser particle; - three figures contamination code; - new procedure of sample pre-treatment when automated laser counter method are used.