航空航天系列 液压滤芯试验方法 第3部分：过滤效率和截留能力

[中文适用范围]： 本文件描述了两种在可重复条件下测量航空和航天液压系统中使用的滤芯过滤效率的方法。该方法可用于根据 ISO 14085-1 评估滤芯的整体特性，也可单独使用。由于滤芯的过滤效率在其使用寿命期间会因堵塞而发生变化，因此本测试方法规定使用在线粒子计数器进行连续测量，连续注入测试污染物并再循环未被测试滤芯保留的粒子，直到滤芯两端的压差达到给定的最终或“终端”值。本文件允许在稳定或循环流动条件下测量效率。它也适用于在循环流动测试时测量滤芯产生的稳定污染水平。本文件不适用于在重复使用条件下鉴定滤芯；这只能通过为此目的开发的特定测试协议来完成，包括实际使用条件，例如工作流体或污染。应用本文得到的测试数据可用于比较航空液压滤芯的性能。 [外文原描述]： This document describes two methods to measure in repeatable conditions the filtration efficiency of filter elements used in aviation and aerospace hydraulic fluid systems. It can be applied when evaluating the overall characteristics of a filter element according to ISO 14085-1, or separately. Since the filtration efficiency of a filter element can change during its service life as it is clogging, this test method specifies its continuous measurement by using on-line particle counters with continuous injection of test contaminant and recirculation of particles not retained by the test filter element until the differential pressure across the element reaches a given final or “terminal” value. This document allows the efficiency to be measured under both steady or cyclic flow conditions. It is also applicable to measuring the stabilized contamination levels that are produced by the filter element while testing with cyclic flow. This document is not applicable to qualifying a filter element under replicate conditions of service; this can only be done by a specific test protocol developed for the purpose, including actual conditions of use, e.g. the operating fluid or contamination. The test data resulting from application of this document can be used to compare the performance of aerospace hydraulic filter elements.