ISO 21360-1:2020

مواصفة قياسية دولية   PUBLISHED

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

المجال

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.

إعداد
15 يونيو 2020

الملفات

null صفحات
null null
 

المواصفات ذات العلاقة

revises
ISO 21360-1:2012
 
مسحوبة
مواصفة قياسية دولية
Vacuum technology — Standard methods for measuring vacuum-pump performance — Part 1: General description

الأكثر مبيعاً

GSO 9:2013
 
لائحة فنية خليجية
بطاقات المواد الغذائية المعبأة
BH GSO 9:2015
GSO 9:2013 
لائحة فنية بحرينية
بطاقات المواد الغذائية المعبأة
BH GSO 150-2:2015
GSO 150-2:2013 
مواصفة قياسية بحرينية
فترات صلاحية المنتجات الغذائية - الجزء الثاني : فترات الصلاحية الاختيارية
GSO 150-2:2013
 
مواصفة قياسية خليجية
فترات صلاحية المنتجات الغذائية - الجزء الثاني : فترات الصلاحية الاختيارية

اعتمدت مؤخراً

ISO/IEC/IEEE 14764:2022
 
مواصفة قياسية دولية
Software engineering — Software life cycle processes — Maintenance
ISO 21490:2022
 
مواصفة قياسية دولية
Rubber and rubber products — Determination of 2-mercaptobenzothiazole content by high performance liquid chromatography (HPLC)
ISO 1888:2022
 
مواصفة قياسية دولية
Textile glass — Staple fibres or filaments — Determination of average diameter
ISO 10365:2022
 
مواصفة قياسية دولية
Adhesives — Designation of main failure patterns