ISO 6145-6:2017规定了使用临界流孔系统从纯气体或气体预混合物动态制备含有至少两种气体（通常是其中之一是互补气体）的校准气体混合物的方法。 该方法主要适用于制备不反应气体的混合物，这些非反应性气体与在临界流动孔系统或辅助设备内形成气体回路的任何材料不反应。如果使用适当数量的临界流通孔，具有允许多组分混合物如二元混合物容易地制备的优点。 通过选择临界流量孔的适当组合，可实现1×104的稀释比。 尽管更特别适用于在大气压下制备气体混合物，但该方法还提供了在大于大气压的压力下制备校准气体混合物的可能性。上游压力需要比下游压力高至少两倍。 本文档涵盖的流量范围从1 ml/min延伸到10 l/min。

ISO 6145-6:2017 specifies a method for the dynamic preparation of calibration gas mixtures containing at least two gases (usually one of them is a complementary gas) from pure gases or gas pre-mixtures using critical flow orifices systems. The method applies principally to the preparation of mixtures of non-reactive gases that do not react with any of the materials forming the gas circuit inside the critical flow orifices system or auxiliary equipment. It has the merit of allowing multi-component mixtures to be prepared as readily as binary mixtures if an appropriate number of critical flow orifices are used. By selecting appropriate combinations of critical flow orifices, a dilution ratio of 1 × 104 is achievable. Although it is more particularly applicable to the preparation of gas mixtures at atmospheric pressure, the method also offers the possibility of preparing calibration gas mixtures at pressures greater than atmospheric. The upstream pressure will need to be at least two times higher than downstream pressure. The range of flow rates covered by this document extends from 1 ml/min to 10 l/min.