本标准规定了在封闭管道中测量单相流体（气体或液体）流量时，示踪（稀释）方法的使用。这种测量方法仅适用于单相均质流体混合物。本标准的制定是为了满足基于使用示踪法测量流体流量的基本原理的通用参考的需要。1977年发布的ISO标准涉及气体流动的示踪方法；这些在2001年被撤回，在这个问题上留下了空白。在互联网上搜索这个主题可以找到大量的文件、标准、参考资料、顾问和制造商。大多数论文、标准和产品都是针对非常具体的应用，并且只针对这些需求提供详细的指导。本标准定义了智能考虑任何应用的示踪方法所需的术语和原则。

This Standard defines the use of tracer (dilution) methods in the measurement of single-phase fluid (gas or liquid) flows in closed conduits. This method of measurement is applicable only to single-phase homogeneous fluid mixtures. This Standard was developed to fill the need for a generalized reference based on fundamental principles to measure fluid flow using tracer methods. ISO standards issued in 1977 addressed tracer methods for gas flows; these were withdrawn in 2001, leaving a void on this subject. An internet search on this subject will find a large number of documents, standards, references, consultants, and manufacturers. Most of the papers, standards, and products are for very specific applications and provide detailed guidance only for those needs. This Standard defines the terms and principles needed for intelligent consideration of tracer methods for any application.