用插入圆形横截面管道中的压差装置测量流体流量.第6部分:楔形流量计

[中文适用范围]： 本文件规定了楔形流量计的几何形状和使用方法（安装和操作条件），当楔形流量计插入完全运行的管道中时，以确定管道中流动的流体的流速。 注 1：由于未校准的楔形流量计的不确定度对于特定应用而言可能太大，因此根据第 7 章校准流量计可能被认为是必要的。 本文件给出了校准要求，如果适用，则可在校准的雷诺数范围。 第 7 条对于类似设计但不属于本文件范围的仪表校准也可以提供有用的指导。 它还提供计算流量的背景信息，并与 ISO 5167-1 中给出的要求结合应用。 本文件仅适用于楔形流量计，其中流量在整个测量部分保持亚音速并且流体可被视为单相。 未经校准的楔形流量计只能在管道尺寸、粗糙度、β（或楔形比）和雷诺数的指定限制内使用。 不适用于脉动流量的测量。 它不包括在内径小于 50 mm 或大于 600 mm 的管道中或管道雷诺数低于 1 × 104 的情况下使用未经校准的楔形流量计。 注 2 楔形流量计的主要元件包括：特定几何形状的楔形限制。 可提供楔形流量计的替代设计；然而，在撰写本文时，没有足够的数据来完全表征这些设备，因此这些仪表根据第 7 条进行校准。 [外文原描述]： This document specifies the geometry and method of use (installation and operating conditions) of wedge meters when they are inserted in a conduit running full to determine the flow rate of the fluid flowing in the conduit. NOTE 1 As the uncertainty of an uncalibrated wedge meter can be too large for a particular application, it could be deemed essential to calibrate the flow meter according to Clause 7. This document gives requirements for calibration which, if applied, are for use over the calibrated Reynolds number range. Clause 7 could also be useful guidance for calibration of meters of similar design but which fall outside the scope of this document. It also provides background information for calculating the flow rate and is applicable in conjunction with the requirements given in ISO 5167‑1. This document is applicable only to wedge meters in which the flow remains subsonic throughout the measuring section and where the fluid can be considered as single-phase. Uncalibrated wedge meters can only be used within specified limits of pipe size, roughness, β (or wedge ratio) and Reynolds number. It is not applicable to the measurement of pulsating flow. It does not cover the use of uncalibrated wedge meters in pipes whose internal diameter is less than 50 mm or more than 600 mm, or where the pipe Reynolds numbers are below 1 × 10 4 . NOTE 2 A wedge meter has a primary element which consists of a wedge-shaped restriction of a specific geometry. Alternative designs of wedge meters are available; however, at the time of writing there is insufficient data to fully characterize these devices, and therefore these meters are calibrated in accordance with Clause 7.