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
文件草案.一般通风用空气过滤器.第4部分:确定最小部分试验效率的调节方法(ISO/DIS 16890-4-2020);德文和英文版本prEN ISO 16890-4:2020