IEC_TS_62720-2017.pdf

IEC TS 62720 Edition 2.0 2017-01 TECHNICAL SPECIFICATION Identification of units of measurement for computer-based processing IEC T S 62720:2017-01(en)THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2017 IEC,Geneva,Switzerland All rights reserved.Unless otherwise specified,no part of this publication may be reproduced or utilized in any form or by any means,electronic or mechanical,including photocopying and microfilm,without permission in writing from either IEC or IECs member National Committee in the country of the requester.If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,please contact the address below or your local IEC member National Committee for further information.IEC Central Office Tel.:+41 22 919 02 11 3,rue de Varemb Fax:+41 22 919 03 00 CH-1211 Geneva 20 infoiec.ch Switzerland www.iec.ch About the IEC The International Electrotechnical Commission(IEC)is the leading global organization that prepares and publishes International Standards for all electrical,electronic and related technologies.About IEC publications The technical content of IEC publications is kept under constant review by the IEC.Please make sure that you have the latest edition,a corrigenda or an amendment might have been published.IEC Catalogue-webstore.iec.ch/catalogue The stand-alone applica tion for consulting the entir e bibliogr aphical informa tion on IEC International Standar ds,Technical Specifica tions,Technical Reports and other documents.Av ailable for PC,Mac OS,Android Tablets and iPad.IEC publications search-www.iec.ch/searchpub The adv anced sear ch enables to find IEC publications by a var iety of cr iter ia(refer ence number,text,technica l committee,).It also gives infor ma tion on pr ojects,replaced and w ithdraw n publications.IEC Just Published-webstore.iec.ch/justpublished Stay up to da te on all new IEC publications.Just Published details all new publica tions released.Av ailable online and also once a month by email.Electropedia-www.electropedia.org The w or lds leading online dictionary of electronic and electrical terms containing 20 000 terms and definitions in English and Fr ench,w ith equiv alent ter ms in 16 additional languages.Also k nown as the Inter national Electr otechnical Vocabulary(IEV)online.IEC Glossary-std.iec.ch/glossary 65 000 electrotechnical terminology entries in English and Fr ench extracted fr om the Terms and Definitions clause of IEC publica tions issued since 2002.Some entr ies hav e been collected from ear lier publications of IEC TC 37,77,86 and CISPR.IEC Customer Serv ice Centre-webstore.iec.ch/csc If you w ish to giv e us your feedback on this publication or need fur ther assistance,plea se contact the Customer Ser v ice Centre:csciec.ch.IEC TS 62720 Edition 2.0 2017-01 TECHNICAL SPECIFICATION Identification of units of measurement for computer-based processing INT ERNAT IONAL ELECT ROT ECHNICAL COMMISSION ICS 01.040.35;01.060;35.240.60 ISBN 978-2-8322-3863-9 Registered t rademark of the Internat ional Electrotechnica l Commission Warning!Mak e sure that you obtained this publication from an authorized distributor.2 IEC TS 62720:2017 IEC 2017 CONTENTS FOREWORD.3 INTRODUCTION.5 1 Scope.6 2 Normative references.6 3 Terms and definitions.6 4 Relations between quantities,units and their systems.13 4.1 General.13 4.2 The International System of Quantities and the International System of Units.13 4.3 Other systems of quantities and units.15 4.4 List of quantities and units.15 5 Prefixes and prefix symbols.15 5.1 General.15 5.2 Formation of multiples and factors.15 5.3 Usage of SI prefixes and SI prefix symbols.17 5.3.1 General.17 5.3.2 Combination of SI prefixes,SI prefix symbols,names of units and symbols for units.17 5.3.3 Use of power exponentials in conjunction with SI prefixes,SI prefix symbols,names of units or symbols for units.18 5.3.4 Restrictions on combining SI prefixes,SI prefix symbols,names of units and symbols for units.18 5.4 Selecting SI prefixes and SI prefix symbols.18 6 Identification of units.19 Annex A(informative)Information about units.21 Annex B(normative)Identifiers for units and quantities.22 Annex C(informative)Quantities and assigned units of measure.23 Bibliography.86 Figure 1 International Registration Data Identifier(IRDI).19 Table 1 Examples of generic concepts for individual quantities.7 Table 2 Base quantity and base unit.8 Table 3 Base quantities.10 Table 4 Base quantities and base units in the International System of Units.14 Table 5 Representation of base quantities in the International System of Units.14 Table 6 Formation of multiples and factors of units to the base of 10.16 Table 7 Formation of multiples of units to the base of 2.17 Table 8 Units that are used without prefixes or prefix symbols.18 Table C.1 Codes of quantities.23 Table C.2 Codes of units.35 IEC TS 62720:2017 IEC 2017 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ IDENTIFICATION OF UNITS OF MEASUREMENT