1.1 本规程涵盖了低压多组分气体混合物制备的实验室程序。该技术适用于以百分比水平混合组分，并可通过对先前制备的基础混合物进行稀释扩展到较低浓度。可获得的最大混合压力取决于所用压力计的范围，但通常约为101 kPa（760 毫米汞柱）。在最大混合压力下，成分不得冷凝。 1.2 歧管混合系统中可能存在小泄漏，这将妨碍该方法适用于氧或氮浓度为百万分之一的混合物。 1.3 这种做法仅限于那些彼此、歧管或混合气缸不反应的化合物。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 3.1 实验室制备已知成分的混合气体需要为色谱和其他类型的分析仪器的校准提供主要标准。

1.1 This practice covers a laboratory procedure for the preparation of low-pressure multicomponent gas blends. The technique is applicable to the blending of components at percent levels and can be extended to lower concentrations by performing dilutions of a previously prepared base blend. The maximum blend pressure obtainable is dependent upon the range of the manometer used, but ordinarily is about 101 kPa (760 mm Hg). Components must not be condensable at the maximum blend pressure. 1.2 The possible presence of small leaks in the manifold blending system will preclude applicability of the method to blends containing part per million concentrations of oxygen or nitrogen. 1.3 This practice is restricted to those compounds that do not react with each other, the manifold, or the blend cylinder. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 3.1 The laboratory preparation of gas blends of known composition is required to provide primary standards for the calibration of chromatographic and other types of analytical instrumentation.