.12:2017 涡街流量计测量气体

[中文适用范围]： 适用范围如下：(a) 提供全通径涡街流量计的通用信息，包括术语表及用于性能标定的一组工程计算公式；(b) 描述一种涡街流量计，其通过在封闭管道内安装的一个或多个钝体产生交替脱落的涡街；(c) 说明如何利用涡街脱落频率确定流速，进而推算体积、质量或能量流量，以及特定时间间隔内通过流量计的累计气体流量；(d) 仅适用于封闭管道内单相气体流动，且流动状态为稳定或随时间缓慢变化；用于贸易计量时，流量计输出的流量值须处于稳态流量的允许限值之内；(e) 说明涡街流量计的物理结构，并提出对仪表进行检验、认证及材料可追溯性的要求；(f) 分析气体物性、安装条件及工艺条件对流量计性能的潜在影响。 [外文原描述]： Addresses the following: (a) provides generic information on full-bore vortex shedding flowmeters, including glossary, and sets of engineering equations useful in specifying performance; (b) describes vortex shedding flowmeters in which alternating vortices are shed from one or more bluff bodies installed in a closed conduit; (c) describes how the vortex shedding frequency is used to determine the velocity to infer the volume, mass, and/or energy flow rate and the total gas flow through the meter over a specific time interval; (d) applies only to single phase gas flows in closed conduit that are steady or vary slowly in time. For fiscal measurement, the output of the flow rate shall be within the acceptable limits of steady state flow rate; (e) describes the physical components of vortex shedding flowmeters and identifies need for inspection, certification, and material traceability; (f) addresses the effect of gas properties, installation, and process conditions that may affect the me