标准摘要
[中文适用范围]： ISO 6145 的这一部分指定了一种使用扩散来制备成分摩尔分数范围为 10−9 至 10−3 的校准气体混合物的动态方法。 通过使用该方法可以实现不大于±2%的测量相对扩展不确定度U，通过将相对组合标准不确定度乘以覆盖因子k = 2获得。 通过保持扩散源和使用地点之间的路径尽可能短，该方法可用于产生有机组分的低浓度校准气体，这些组分在室温下为液体，沸点范围为约40℃至 160°C。 ISO 6145的这一部分不仅适用于在环境和室内空气浓度水平下生成各种碳氢化合物的校准气体混合物，而且还适用于生成低浓度的水气体混合物。 [外文原描述]： ISO 6145-8:2005 specifies a dynamic method using diffusion for the preparation of calibration gas mixtures containing component mole fractions ranging from 10 -9 to 10 -3 . 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 ± 2 % can be achieved by using this method. By keeping the path between the diffusion source and place of use as short as possible, the method can be applied for the generation of low-concentration calibration gases of organic components that are liquid at room temperature, with boiling points ranging from about 40 °C to 160 °C. ISO 6145-8:2005 is applicable not only for the generation of calibration gas mixtures of a wide range of hydrocarbons at ambient and indoor air concentration levels, but also for the generation of low-concentration gas mixtures of water.
英文名称Gas analysis — Preparation of calibration gas mixtures using dynamic volumetric methods — Part 8: Diffusion method