本标准仅适用于基于声信号传输时间测量的超声波流量计。此外，本标准仅涉及当用于测量具有均匀声学特性且在完全填充的封闭管道中流动的液体的体积流量时，此类流量计的应用。本标准不包括通过测量偏差、散射（多普勒流量计）或声学信号相关性得出体积流量的超声波流量计。本标准规定:（a）本标准所涵盖的超声波流量计的工作原理说明；（b） 错误源和性能验证程序的说明；（c） 一套通用的术语、符号、定义和规范。

This Standard applies only to ultrasonic flowmeters that base their operation on the measurement of transit times of acoustic signals. Further, this Standard concerns only the application of such meters when used to measure the volumetric flow rate of a liquid exhibiting homogeneous acoustic properties and flowing in a completely filled closed conduit. Not covered by this Standard are ultrasonic flowmeters that derive volumetric flow rate from measurements of the deviation, scattering (Doppler flowmeter), or correlation of acoustic signals. This Standard provides: (a) a description of the operating principles employed by the ultrasonic flowmeters covered in this Standard; (b) a description of error sources and performance verification procedures; (c) a common set of terminology, symbols, definitions, and specifications.