1.1 本指南旨在提供核工业中使用的高石墨化、低表面积材料的方法学信息。它适用于77℃下的氮吸附测量 用于表征石墨孔结构，例如:( 1. )比表面积；( 2. )开孔的累积体积（孔径小于约300 纳米）；和( 3. )作为孔径函数的孔隙体积分布（对于小于约30的孔径 纳米）。这些特性与石墨在氧化环境中的反应性、石墨保留裂变产物的能力以及气体通过石墨孔隙系统的传输有关。 1.2 用气体吸附法表征核石墨的比表面积（也称为Brunauer-Emmett-Teller“BET”方法）和孔隙率受到核石墨的低比表面积、弱吸附相互作用以及气体中表面位置的能量和结构不均匀性的挑战- 可进入的孔隙。本指南提供了与氮吸附法相关的建议和实用信息，包括样本制备、实验条件选择、数据处理和结果解释指南。 1.3 用于核石墨的其他孔隙度表征方法，例如77℃下的氪吸附 K、 氩在任一温度下的吸附 K或87 K、 氦比重计（试验方法 B923 )和汞侵入孔隙测定法不在本指南的范围内。 1.4 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.5 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。 1.6 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。

1.1 The purpose of this Guide is to provide methodologic information specific to highly graphitized, low surface area materials used in the nuclear industry. It applies to nitrogen adsorption measurements at 77 K for the characterization of graphite pore structure, such as: ( 1 ) specific surface area; ( 2 ) cumulative volume of open pores (for pore sizes less than about 300 nm); and ( 3 ) distribution of pore volumes as a function of pore sizes (for pore sizes less than about 30 nm). These properties are related to graphite’s reactivity in oxidative environments, graphite’s ability to retain fission products, and gas transport through graphite’s pore system. 1.2 Characterization of surface area (also known as the Brunauer-Emmett-Teller “BET” method) and porosity in nuclear graphite by gas adsorption is challenged by nuclear graphite’s low specific surface area, weak adsorption interactions, and energetic and structural heterogeneity of surface sites in gas-accessible pores. This guide provides recommendations and practical information related to the nitrogen adsorption method, including guidance on specimen preparation, selection of experimental conditions, data processing, and interpretation of results. 1.3 Other porosity characterization methods used for nuclear graphite, such as krypton adsorption at 77 K, argon adsorption at either 77 K or 87 K, helium pycnometry (Test Method B923 ), and mercury intrusion porosimetry, are not in the scope of this guide. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 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. 1.6 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.