本文件定义了术语和符号，并确立了当将差压装置（孔板、喷嘴、文丘里管、锥度计和楔形计）插入满管的圆形横截面导管时，测量和计算导管内流体流速的方法的一般原则。本文件还规定了测量方法、安装和流量测量不确定度测定的一般要求。 ISO？标准5167（所有部分）仅适用于整个测量段保持亚音速且流体可视为单一流体的流动- 阶段不适用于脉动流量的测量。

This document defines terms and symbols and establishes the general principles for methods of measurement and computation of the flow rate of fluid flowing in a conduit by means of pressure differential devices (orifice plates, nozzles, Venturi tubes, cone meters, and wedge meters) when they are inserted into a circular cross-section conduit running full. This document also specifies the general requirements for methods of measurement, installation and determination of the uncertainty of the measurement of flow rate. ISO？5167 (all parts) is applicable only to flow that remains subsonic throughout the measuring section and where the fluid can be considered as single-phase. It is not applicable to the measurement of pulsating flow.