ISO 21360-1:2020 真空技术 测量真空泵性能的标准方法 第1部分：一般说明

标准编号：ISO 21360-1:2020

中文名称：真空技术 测量真空泵性能的标准方法 第1部分：一般说明

英文名称：Vacuum technology — Standard methods for measuring vacuum-pump performance — Part 1: General description

发布日期：2020-06

标准范围

本文件规定了三种测量体积流量的方法，以及一种测量真空泵的基础压力、压缩比和临界背压的方法。第一种测量体积流量的方法（流量法）是基本概念，即在测量入口压力的同时，向泵内注入稳定的气流。实际上，气体流量的测量可能很复杂或不精确。因此，还规定了另外两种方法，避免直接测量吞吐量。当入口压力非常小（在高真空或超高真空条件下），流量非常小时，使用第二种测量体积流量的方法（孔板法）。它基于测量两室试验穹顶内的压力比，其中两个室由带圆形孔板的墙隔开。第三种测量体积流量的方法（泵降法）非常适合自动测量。这是基于大型船只的疏散。根据泵送间隔前后的两个压力以及试验穹顶的体积计算体积流量。不同的影响，如泄漏率和解吸率、泵送间隔期间近等熵膨胀导致的气体冷却，以及低压下分子流导致测试圆顶和泵之间连接管线中的流动阻力增加，都会影响压力测量结果和产生的体积流量。所需测量方法的选择取决于特定类型真空泵的性能，例如，临界背压的测量仅适用于需要背压泵的真空泵。在真空泵上测量但本文件未规定的所有数据（例如功耗测量）均在特定的泵标准中定义。

This document specifies three methods for measuring the volume flow rate and one method each for measuring the base pressure, the compression ratio, and the critical backing pressure of a vacuum pump.The first method for measuring the volume flow rate (the throughput method) is the basic concept, in which a steady gas flow is injected into the pump while the inlet pressure is measured. In practice, the measurement of gas throughput may be complicated or inexact. For this reason, two other methods are specified which avoid the direct measurement of throughput.The second method for measuring the volume flow rate (the orifice method) is used when there is very small throughput at very small inlet pressures (under a high or ultra-high vacuum). It is based on measuring the ratio of pressures in a two-chamber test dome in which the two chambers are separated by a wall with a circular orifice.The third method for measuring the volume flow rate (the pump-down method) is well suited for automated measurement. It is based on the evacuation of a large vessel. The volume flow rate is calculated from two pressures, before and after a pumping interval, and from the volume of the test dome. Different effects, such as leak and desorption rates, gas cooling by nearly isentropic expansion during the pumping interval, and increasing flow resistance in the connection line between test dome and pump caused by molecular flow at low pressures, influence the results of the pressure measurement and the resulting volume flow rate.The choice of the required measurement methods depends on the properties of the specific kinds of vacuum pump, e.g. the measurement of the critical backing pressure is only necessary for vacuum pumps which need a backing pump. All data that are measured on a vacuum pump, but not specified in this document (e.g. measurement of power consumption), are defined in the specific pump standard.

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