ISO 6145-9:2009是一系列涉及用于制备校准气体混合物的动态体积法的国际标准之一。该部分规定了连续生产含有一种或多种易冷凝组分的校准气体混合物的方法。通过使用该方法可以获得通过将相对组合标准不确定度乘以不大于±1％的覆盖系数k = 2而获得的相对扩大的测量不确定度U。 与ISO 6145其他部分中提出的方法不同，本部分中描述的方法不需要精确的流量测量，因为流量没有出现在计算体积分数的方程中。 易冷凝的气体和蒸气通常被吸附在表面上，因此难以通过静态方法制备包含这些组分的精确已知组成的稳定的校准气体混合物。此外，这些校准气体混合物不能保持在接近饱和极限的压力下，而不会发生冷凝。饱和方法可用于制备这种类型的混合物

ISO 6145-9:2009 is one of a series of International Standards dealing with various dynamic volumetric methods used for the preparation of calibration gas mixtures. This part specifies a method for continuous production of calibration gas mixtures containing one or more readily condensable components. A relative expanded uncertainty of measurement, U, obtained by multiplying the relative combined standard uncertainty by a coverage factor k = 2, of not greater than ±1 %, can be obtained using this method. Unlike the methods presented in the other parts of ISO 6145, the method described in this part does not require accurate measurement of flow rates since flow rates do not appear in the equations for calculation of the volume fraction. Readily condensable gases and vapours commonly become adsorbed on surfaces, and it is therefore difficult to prepare stable calibration gas mixtures of accurately known composition, containing such components, by means of static methods. In addition, these calibration gas mixtures cannot be maintained under a pressure near the saturation limit without the occurrence of condensation. The saturation method can be employed to prepare mixtures of this type.