IEC TS 62720:2017
(Main)Identification of units of measurement for computer-based processing
Identification of units of measurement for computer-based processing
IEC TS 62720:2017(E) specifies identifiers for units to support computer-based processing of product data. It provides a survey of quantities with associated collections of internationally standardized as well as non–standardized units used in business and science.
It covers any standard or non-standard units of measure currently in use, in two or more distinct ethno-linguistic groups or nations, at least in one domain of industry, for which an explicit method of conversion to a known standard unit of measure or its equivalent is well documented or evident from external references.
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IEC TS 62720 ®
Edition 2.0 2017-01
TECHNICAL
SPECIFICATION
Identification of units of measurement for computer-based processing
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IEC TS 62720 ®
Edition 2.0 2017-01
TECHNICAL
SPECIFICATION
Identification of units of measurement for computer-based processing
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 01.040.35; 01.060; 35.240.60 ISBN 978-2-8322-3863-9
– 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
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IDENTIFICATION OF UNITS OF MEASUREMENT
FOR COMPUTER-BASED PROCESSING
FOREWORD
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The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
International Standard IEC 62720, which is a technical specification, has been prepared by
subcommittee 3D: Product properties and classes and their identification, of IEC technical
committee 3: Information structures and elements, identification and marking principles,
documentation and graphical symbols.
– 4 – IEC TS 62720:2017 © IEC 2017
This second edition cancels and replaces the first edition published in 2013. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the detailed description of the units is contained in the IEC CDD (http://cdd.iec.ch/ ) and
removed from this document;
b) Annex B contains the reference to the IEC CDD;
c) Annex C contains an abridged listing of quantities, units and their identifying codes;
d) Annexes D and E are removed.
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
3D/282/DTS 3D/289/RVC
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
___________
Website checked on 2016-06-10.
INTRODUCTION
For the interpretation of documents such as data sheets, catalogues, or other product related
documentation, units of measure play an inconspicuous but important role. All quantitative
data can be prone to misinterpretation if its unit of measure is unclear or wrong. Thus, there is
a strong requirement to unambiguously identify units of measure and ensure that each unit of
measure and its underlying quantity is clearly specified.
As a consequence there is a need to provide computer interpretable identifiers for units of
measure. This document assigns identifiers to many standard or non-standard units of
measure currently in use.
To ensure timely and fast maintenance of the collection, the content of the document is
provided in the IEC Common Data Dictionary (CDD), thus making possible easy maintenance
and fast introduction of missing units of measure and quantities.
...
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