气体分析. 校准气体混合物的制备. 第1部分: 用于I类混合物的重量分析法

[中文适用范围]： ISO 6142 的这一部分规定了一种在钢瓶中制备校准气体混合物的重量分析方法，该方法具有一种或多种组分的物质含量分数（量分数）的可追溯值。 ISO 6142 的这一部分描述了计算与每种成分的含量分数相关的不确定度的方法。 这种不确定度计算需要评估由于称量过程、组分纯度、混合物的稳定性以及最终混合物的验证等因素对不确定度的贡献。 ISO 6142 的这一部分仅适用于气态或完全汽化成分的混合物，这些成分可能以气态或液态引入气瓶。 ISO 6142 的本部分涵盖二元和多组分气体混合物（包括天然气类混合物）。 ISO 6142 的本部分不包括在单一工艺中批量生产多种混合物的方法。 ISO 6142 的一部分要求评估混合物在其预期寿命（最大储存寿命）内的稳定性，但不适用于无意间相互反应的组分。 ISO 6142 的这一部分还要求对用于制备混合物的每种母体气体或液体中的杂质进行评估和量化。 [外文原描述]： ISO 6142-1:2015 specifies a gravimetric method for the preparation of calibration gas mixtures in cylinders with traceable values for the amount-of-substance fraction (amount fraction) of one or more components. This part of ISO 6142 describes a method for calculating the uncertainty associated with the amount fraction of each component. This uncertainty calculation requires the evaluation of the contributions to the uncertainty due to factors including the weighing process, the purity of the components, the stability of the mixture, and the verification of the final mixture. ISO 6142-1:2015 is only applicable to mixtures of gaseous or totally vaporized components, which may be introduced into the cylinder in the gaseous or liquid state. Both binary and multi-component gas mixtures (including natural-gas type mixtures) are covered by this part of ISO 6142. Methods for the batch production of more than one mixture in a single process are not included in this part of ISO 6142. ISO 6142-1:2015 requires estimation of the stability of the mixture for its intended life time (maximum storage life), but it is not for use with components that react with each other unintentionally. This part of ISO 6142 also requires the impurities in each parent gas or liquid used in the preparation of the mixture to be assessed and quantified.