ISO 21360-1:2020
(Main)Vacuum technology — Standard methods for measuring vacuum-pump performance — Part 1: General description
Vacuum technology — Standard methods for measuring vacuum-pump performance — Part 1: General description
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.
Technique du vide — Méthodes normalisées pour mesurer les performances des pompes à vide — Partie 1: Description générale
General Information
Relations
Buy Standard
Standards Content (Sample)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 21360-1
ISO/TC 112
Vacuum technology — Standard
Secretariat: DIN
methods for measuring vacuum-pump
Voting begins on:
2020-02-25 performance —
Voting terminates on:
Part 1:
2020-04-21
General description
Technique du vide — Méthodes normalisées pour mesurer les
performances des pompes à vide —
Partie 1: Description générale
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 21360-1:2020(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2020
ISO/FDIS 21360-1:2020(E)
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
ISO/FDIS 21360-1:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 3
5 Test methods . 4
5.1 Volume flow rate (pumping speed) measurement by the throughput method . 4
5.1.1 General. 4
5.1.2 Test dome for the throughput method . 5
5.1.3 Experimental setup . 6
5.1.4 Determination of the volume flow rate . 6
5.1.5 Measuring procedure . 7
5.1.6 Measuring uncertainties . 8
5.1.7 Evaluation of the measurement . 8
5.2 Volume flow rate (pumping speed) measurement by the orifice method . 8
5.2.1 General. 8
5.2.2 Test dome for the orifice method . 8
5.2.3 Experimental setup . 9
5.2.4 Determination of the volume flow rate .10
5.2.5 Measuring procedure for the orifice method .11
5.2.6 Adjustment of the pressure-measuring gauges .11
5.2.7 Measurement of the volume flow rate .11
5.2.8 Measuring uncertainties .11
5.2.9 Evaluation of the measurement .12
5.3 Volume flow rate (pumping speed) measurement by the pump-down method .13
5.3.1 General.13
5.3.2 Test dome for the pump-down method .13
5.3.3 Quick-acting valve .14
5.3.4 Experimental setup .14
5.3.5 Determination of the volume flow rate .15
5.3.6 Measuring procedure .16
5.3.7 Limits of applicability .17
5.3.8 Evaluation of the measurement .17
5.3.9 Measurement uncertainty .17
5.4 Measurement of the base pressure .17
5.4.1 Operating conditions .17
−4
5.4.2 Test procedure for pumps with a base pressure >10 Pa .18
−4
5.4.3 Test procedure for pumps with a base pressure <10 Pa .18
5.4.4 Evaluation of the measurement .18
5.5 Measurement of the compression ratio and the critical backing pressure .18
5.5.1 Experimental setup .19
5.5.2 Determination of the compression ratio and the critical backing pressure .19
5.5.3 Measurement procedure .20
5.5.4 Measurement uncertainty .21
5.5.5 Evaluation of the measurements .21
5.5.6 Specific recommendations for extremely high compression ratio
measurements.21
Annex A (informative) Mean free path of some important gases .23
Annex B (informative) Measuring uncertainties .24
Bibliography .27
ISO/FDIS 21360-1:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 21360-1 was prepared by Technical Committee ISO/TC 112, Vacuum technology.
This second edition cancels and replaces the first edition ISO 21360-1:2012, of which it constitutes a
minor revision. The changes compared to the previous edition are as follows:
— Note in 3.3 has been deleted
— K in 3.7 has been corrected
— 3.9 the definition of the volume has been changed to "is the volume of transported gas"
— Figure 1 has been corrected
— Figure 2 has been corrected
— 5.2.7: change to "for at least 60s" instead of " for the following minute".
A list of all parts in the ISO 21360 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
ISO/FDIS 21360-1:2020(E)
Introduction
This part of ISO 21360 is a basic standard for measuring the performance data of vacuum pumps.
The methods specified here are well known from existing national and International Standards.
In developing this part of ISO 21360, the aim has been to provide a single document containing the
measurements of performance data of vacuum pumps and to simplify the future development of specific
vacuum pump standards.
Specific vacuum pump standards will contain a suitable selection of measurement methods from this
part of ISO 21360 in order to determine the performance data, limiting values and specific operational
conditions on the basis of the specific properties of the particular kind of pump. Whenever a discrepancy
exists between this part of ISO 21360 and the specific standard, it is the specific standard which is valid.
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 21360-1:2020(E)
Vacuum technology — Standard methods for measuring
vacuum-pump performance —
Part 1:
General description
1 Scope
This part of ISO 21360 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
du
...
INTERNATIONAL ISO
STANDARD 21360-1
Second edition
2020-06
Vacuum technology — Standard
methods for measuring vacuum-pump
performance —
Part 1:
General description
Technique du vide — Méthodes normalisées pour mesurer les
performances des pompes à vide —
Partie 1: Description générale
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 3
5 Test methods . 4
5.1 Volume flow rate (pumping speed) measurement by the throughput method . 4
5.1.1 General. 4
5.1.2 Test dome for the throughput method . 5
5.1.3 Experimental setup . 6
5.1.4 Determination of the volume flow rate . 7
5.1.5 Measuring procedure . 8
5.1.6 Measuring uncertainties . 8
5.1.7 Evaluation of the measurement . 8
5.2 Volume flow rate (pumping speed) measurement by the orifice method . 9
5.2.1 General. 9
5.2.2 Test dome for the orifice method . 9
5.2.3 Experimental setup .10
5.2.4 Determination of the volume flow rate .11
5.2.5 Measuring procedure for the orifice method .12
5.2.6 Adjustment of the pressure-measuring gauges .12
5.2.7 Measurement of the volume flow rate .12
5.2.8 Measuring uncertainties .12
5.2.9 Evaluation of the measurement .13
5.3 Volume flow rate (pumping speed) measurement by the pump-down method .14
5.3.1 General.14
5.3.2 Test dome for the pump-down method .14
5.3.3 Quick-acting valve .15
5.3.4 Experimental setup .15
5.3.5 Determination of the volume flow rate .16
5.3.6 Measuring procedure .17
5.3.7 Limits of applicability .18
5.3.8 Evaluation of the measurement .18
5.3.9 Measurement uncertainty .18
5.4 Measurement of the base pressure .18
5.4.1 Operating conditions .18
−4
5.4.2 Test procedure for pumps with a base pressure >10 Pa .19
−4
5.4.3 Test procedure for pumps with a base pressure <10 Pa .19
5.4.4 Evaluation of the measurement .19
5.5 Measurement of the compression ratio and the critical backing pressure .19
5.5.1 Experimental setup .20
5.5.2 Determination of the compression ratio and the critical backing pressure .20
5.5.3 Measurement procedure .21
5.5.4 Measurement uncertainty .22
5.5.5 Evaluation of the measurements .22
5.5.6 Specific recommendations for extremely high compression ratio
measurements.22
Annex A (informative) Mean free path of some important gases .24
Annex B (informative) Measuring uncertainties .25
Bibliography .28
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 112, Vacuum technology.
This second edition cancels and replaces the first edition (ISO 21360-1:2012), of which it constitutes a
minor revision. The changes compared to the previous edition are as follows:
— Note in 3.3 has been deleted;
— K in 3.7 has been corrected;
— 3.9 the definition of the volume has been changed to "is the volume of transported gas";
— Figure 1 has been corrected;
— Figure 2 has been corrected;
— 5.2.7: change to "for at least 60s" instead of " for the following minute".
A list of all parts in the ISO 21360 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
Introduction
This document is a basic standard for measuring the performance data of vacuum pumps. The methods
specified here are well known from existing national and International Standards. In developing this
document, the aim has been to provide a single document containing the measurements of performance
data of vacuum pumps and to simplify the future development of specific vacuum pump standards.
Specific vacuum pump standards will contain a suitable selection of measurement methods from
this document in order to determine the performance data, limiting values and specific operational
conditions on the basis of the specific properties of the particular kind of pump. Whenever a discrepancy
exists between this document and the specific standard, it is the specific standard which is valid.
INTERNATIONAL STANDARD ISO 21360-1:2020(E)
Vacuum technology — Standard methods for measuring
vacuum-pump performance —
Part 1:
General description
1 Scope
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 resis
...
INTERNATIONAL ISO
STANDARD 21360-1
Second edition
2020-06
Vacuum technology — Standard
methods for measuring vacuum-pump
performance —
Part 1:
General description
Technique du vide — Méthodes normalisées pour mesurer les
performances des pompes à vide —
Partie 1: Description générale
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 3
5 Test methods . 4
5.1 Volume flow rate (pumping speed) measurement by the throughput method . 4
5.1.1 General. 4
5.1.2 Test dome for the throughput method . 5
5.1.3 Experimental setup . 6
5.1.4 Determination of the volume flow rate . 7
5.1.5 Measuring procedure . 8
5.1.6 Measuring uncertainties . 8
5.1.7 Evaluation of the measurement . 8
5.2 Volume flow rate (pumping speed) measurement by the orifice method . 9
5.2.1 General. 9
5.2.2 Test dome for the orifice method . 9
5.2.3 Experimental setup .10
5.2.4 Determination of the volume flow rate .11
5.2.5 Measuring procedure for the orifice method .12
5.2.6 Adjustment of the pressure-measuring gauges .12
5.2.7 Measurement of the volume flow rate .12
5.2.8 Measuring uncertainties .12
5.2.9 Evaluation of the measurement .13
5.3 Volume flow rate (pumping speed) measurement by the pump-down method .14
5.3.1 General.14
5.3.2 Test dome for the pump-down method .14
5.3.3 Quick-acting valve .15
5.3.4 Experimental setup .15
5.3.5 Determination of the volume flow rate .16
5.3.6 Measuring procedure .17
5.3.7 Limits of applicability .18
5.3.8 Evaluation of the measurement .18
5.3.9 Measurement uncertainty .18
5.4 Measurement of the base pressure .18
5.4.1 Operating conditions .18
−4
5.4.2 Test procedure for pumps with a base pressure >10 Pa .19
−4
5.4.3 Test procedure for pumps with a base pressure <10 Pa .19
5.4.4 Evaluation of the measurement .19
5.5 Measurement of the compression ratio and the critical backing pressure .19
5.5.1 Experimental setup .20
5.5.2 Determination of the compression ratio and the critical backing pressure .20
5.5.3 Measurement procedure .21
5.5.4 Measurement uncertainty .22
5.5.5 Evaluation of the measurements .22
5.5.6 Specific recommendations for extremely high compression ratio
measurements.22
Annex A (informative) Mean free path of some important gases .24
Annex B (informative) Measuring uncertainties .25
Bibliography .28
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 112, Vacuum technology.
This second edition cancels and replaces the first edition (ISO 21360-1:2012), of which it constitutes a
minor revision. The changes compared to the previous edition are as follows:
— Note in 3.3 has been deleted;
— K in 3.7 has been corrected;
— 3.9 the definition of the volume has been changed to "is the volume of transported gas";
— Figure 1 has been corrected;
— Figure 2 has been corrected;
— 5.2.7: change to "for at least 60s" instead of " for the following minute".
A list of all parts in the ISO 21360 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
Introduction
This document is a basic standard for measuring the performance data of vacuum pumps. The methods
specified here are well known from existing national and International Standards. In developing this
document, the aim has been to provide a single document containing the measurements of performance
data of vacuum pumps and to simplify the future development of specific vacuum pump standards.
Specific vacuum pump standards will contain a suitable selection of measurement methods from
this document in order to determine the performance data, limiting values and specific operational
conditions on the basis of the specific properties of the particular kind of pump. Whenever a discrepancy
exists between this document and the specific standard, it is the specific standard which is valid.
INTERNATIONAL STANDARD ISO 21360-1:2020(E)
Vacuum technology — Standard methods for measuring
vacuum-pump performance —
Part 1:
General description
1 Scope
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 resis
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.