DIN EN ISO 16890-4 E:2020 文件草案 用于一般通风的空气过滤器 第4部分:确定最小分数测试效率的调节方法 (ISO/DIS 16890-4:2020) 德文版和英文版 prEN ISO 16890-4:2020
Draft Document - Air filters for general ventilation - Part 4: Conditioning method to determine the minimum fractional test efficiency (ISO/DIS 16890-4:2020); German and English version prEN ISO 16890-4:2020