真空技术 - 测量真空泵性能的标准方法 - 第1部分:一般描述

[中文适用范围]： 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基本压力、压缩比和临界前级压力的方法。 第一种测量体积流量的方法（吞吐量法）是基本概念，其中将稳定的气流注入泵中，同时测量入口压力。 在实践中，气体吞吐量的测量可能很复杂或不精确。 因此，指定了另外两种方法来避免直接测量吞吐量。 当入口压力非常小（高真空或超高真空下）且吞吐量非常小时，可以使用第二种测量体积流量的方法（孔板法）。 它基于测量双室测试圆顶中的压力比，其中两个室由带有圆形孔口的壁隔开。 第三种测量体积流量的方法（抽气法）非常适合自动测量。 它基于大型船只的疏散。 体积流量是根据泵送间隔之前和之后的两个压力以及测试圆顶的体积来计算的。 不同的影响，例如泄漏和解吸速率、抽气间隔期间近等熵膨胀导致的气体冷却以及低压下分子流引起的测试圆顶和泵之间的连接管路中的流动阻力增加，都会影响压力测量和测量的结果。 所得的体积流量。 所需测量方法的选择取决于特定类型真空泵的特性，例如，只有需要前级泵的真空泵才需要测量临界前级压力。 所有在真空泵上测量的数据，但本文件中未指定的数据（例如功耗测量）均在特定泵标准中定义。 [外文原描述]： 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.