本文件规定了喷嘴和文丘里管嘴插入满流管道时的几何结构和使用方法（安装和操作条件），以确定管道中流体的流速。 本文件还提供了计算流量的背景信息，并适用于ISO 5167-1中给出的要求。 本文件适用于保持流量的喷嘴和文丘里管喷嘴 整个测量段内的亚音速流体可视为单相。此外，每种装置只能在规定的管道尺寸和雷诺数范围内使用。不适用于脉动流量的测量。它不包括喷嘴和文丘里喷嘴在管道尺寸小于50 mm或大于630 mm，或管道雷诺数低于10000的情况下的使用。 本文件涉及 a） 三种标准 喷嘴: ISA 1932[1]喷嘴； 长半径喷管[2]； 喉部轻敲喷嘴 b） 文丘里管喷嘴。 这三种类型的标准喷嘴在本质上是不同的，并在本文件中单独描述。文丘里管喷嘴与ISA 1932喷嘴具有相同的上游面，但具有发散截面，因此下游取压孔的位置不同，本文对此进行了单独说明。这种设计比类似的喷嘴具有更低的压力损失。 对于所有这些喷嘴和文丘里管喷嘴，已经进行了直接校准实验，在数量、范围和质量上足以使相关的应用系统基于其结果和系数，并具有一定的可预测的不确定性极限。 [1] ISA是国际标准化协会联合会的缩写，1946年被ISO取代。 [2] 长半径喷嘴不同于ISA 1932喷嘴的形状和在测压孔的位置。

This document specifies the geometry and method of use (installation and operating conditions) of nozzles and Venturi nozzles when they are inserted in a conduit running full to determine the flowrate of the fluid flowing in the conduit. This document also provides background information for calculating the flowrate and is applicable in conjunction with the requirements given in ISO 5167‑1. This document is applicable to nozzles and Venturi nozzles in which the flow remains subsonic throughout the measuring section and where the fluid can be considered as single-phase. In addition, each of the devices can only be used within specified limits of pipe size and Reynolds number. It is not applicable to the measurement of pulsating flow. It does not cover the use of nozzles and Venturi nozzles in pipe sizes less than 50 mm or more than 630 mm, or where the pipe Reynolds numbers are below 10 000. This document deals with a) three types of standard nozzles: ISA 1932[1] nozzle; the long radius nozzle[2]; the throat-tapped nozzle b) the Venturi nozzle. The three types of standard nozzle are fundamentally different and are described separately in this document. The Venturi nozzle has the same upstream face as the ISA 1932 nozzle, but has a divergent section and, therefore, a different location for the downstream pressure tappings, and is described separately. This design has a lower pressure loss than a similar nozzle. For all of these nozzles and for the Venturi nozzle direct calibration experiments have been made, sufficient in number, spread and quality to enable coherent systems of application to be based on their results and coefficients to be given with certain predictable limits of uncertainty. [1] ISA is the abbreviation for the International Federation of the National Standardizing Associations, which was superseded by ISO in 1946. [2] The long radius nozzle differs from the ISA 1932 nozzle in shape and in the position of the pressure tappings.