IEC TS 62720:2013

Identification of units of measurement for computer-based processing

IEC/TS 62720:2013 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 concerns 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.

Identification des unités de mesure pour le traitement assisté par ordinateur

La CEI/TS 62720:2013 spécifie les identificateurs d'unités pour prendre en charge le traitement informatique de données de produit. Elle fournit un relevé des grandeurs avec les ensembles associés d'unités tant normalisées à l'échelle internationale que non-normalisées utilisées dans le métier. Elle inclut toutes les unités normalisées ou non-normalisées actuellement en usage, dans au moins deux groupes linguistiques ou nationalités différent(e)s, dont la méthode de conversion dans une unité de mesure connue ou son équivalent est bien documentée ou évidente d'après les références externes.

General Information

• Status: Published
• Publication Date: 21-May-2013
• ICS: 01.060 - Quantities and units
• ICS: 35.240.50 - IT applications in industry
• Technical Committee: SC 3D - Classes, Properties and Identification of products - Common Data Dictionary (CDD)
• Drafting Committee: MT 62720 - TC 3/SC 3D/MT 62720
• Current Stage: DELPUB - Deleted Publication
• Start Date: 25-Jan-2017
• Completion Date: 26-Oct-2025

Relations

• Revised: IEC TS 62720:2017 - Identification of units of measurement for computer-based processing
• Effective Date: 05-Sep-2023

Overview

IEC TS 62720:2013 is a technical specification published by the International Electrotechnical Commission (IEC) that addresses the identification of units of measurement for computer-based processing. This standard provides clear and consistent identifiers for units of measurement, ensuring compatibility and uniform understanding across computer systems that process product data. It covers both internationally standardized units and various non-standard units used in multiple languages and industry domains, provided they have well-documented conversion methods to recognized standard units.

The primary objective of IEC TS 62720:2013 is to support the accurate and effective electronic exchange, interpretation, and processing of unit data, which is essential for global business, engineering, science, and manufacturing applications.

Key Topics

• Units and Quantities Identification
  The standard provides a comprehensive survey of quantities along with associated unit collections, including base units, derived units, and non-SI units accepted internationally.

• International System of Units (SI) and Prefixes
  IEC TS 62720:2013 details SI prefixes and their proper use, including decimal and binary multiples, to facilitate standardized multiplicative factors in data processing.

• Unit Systems and Relations
  The specification explains the relationships between quantities, units, and unit systems, covering the International System of Quantities and other unit systems relevant for computer applications.

• Standardized Identifiers
  The standard defines identifiers for units and quantities, supporting explicit, machine-readable references. This enables software and databases to unambiguously represent measurement units.

• XML Representation
  Annex E offers an informative guide on representing units in XML format, enhancing interoperability between digital systems.

Applications

• Product Data Exchange
  This specification is critical for industries exchanging product information electronically, ensuring that units are consistently understood and interpreted, reducing errors in manufacturing, supply chain, and quality control.

• Scientific and Engineering Software
  Software tools that perform calculations, simulations, or data analysis benefit from standardized unit identifiers, enabling automatic unit conversions and validation.

• International Business and Trade
  Facilitates harmonized communication across ethno-linguistic groups and nations by using universally recognized unit identifiers in business documents, contracts, and compliance reporting.

• Database Management and Metadata Systems
  Databases managing technical or scientific data can use IEC TS 62720:2013 to tag units with standardized codes, improving data integrity and searchability.

Related Standards

• IEC 60050 - International Electrotechnical Vocabulary
  Provides definitions and terminology essential for electrotechnical standards, complementing the unit identifiers in IEC TS 62720.

• ISO 11179 - Metadata Registries
  Supports metadata management practices referenced for unit identification and classification within IEC TS 62720.

• SI Brochures (BIPM)
  The International System of Units (SI) guidelines that underpin the unit definitions and prefixes used in IEC TS 62720.

• XML Standards for Data Interchange
  Standards such as XML Schema Definition (XSD) and related frameworks that support the XML representations of units as outlined in IEC TS 62720 annexes.

---

IEC TS 62720:2013 plays a foundational role in enabling consistent, interoperable measurement unit identification necessary for effective computer-based processing in diverse technical, scientific, and commercial domains. Adopting this standard facilitates precision and clarity in global data exchange, underpinning quality and reliability in digital transformation initiatives.

Standards Content (Sample)

IEC/TS 62720 ®
Edition 1.0 2013-05
TECHNICAL
SPECIFICATION
SPÉCIFICATION
TECHNIQUE
Identification of units of measurement for computer-based processing

Identification des unités de mesure pour le traitement assisté par ordinateur

IEC/TS 62720:2013
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 IEC's 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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les
microfilms, sans l'accord écrit de la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

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About the IEC
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International Standards for all electrical, electronic and related technologies.

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IEC/TS 62720 ®
Edition 1.0 2013-05
TECHNICAL
SPECIFICATION
SPÉCIFICATION
TECHNIQUE
Identification of units of measurement for computer-based processing

Identification des unités de mesure pour le traitement assisté par ordinateur

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XH
ICS 01.060; 35.240.50 ISBN 978-2-83220-823-6

– 2 – TS 62720  IEC:2013
CONTENTS
FOREWORD . 12
INTRODUCTION . 14
1 Scope . 15
2 Normative references . 15
3 Terms and definitions . 15
4 Relations between quantities, units and their systems . 21
4.1 General . 21
4.2 The International System of Quantities and the International System of Units . 21
4.3 Other systems of quantities and units . 23
4.4 Context of units, quantities, and systems of units . 23
5 SI prefixes and SI prefix symbols. 24
5.1 General . 24
5.2 Formation of multiples and factors to the base of 10 . 24
5.3 Formation of multiples to the base of 2 . 25
5.4 Usage of SI prefixes and SI prefix symbols . 25
5.4.1 General . 25
5.4.2 Combination of SI prefixes, SI prefix symbols, names of units and
symbols for units . 25
5.4.3 Use of power exponentials in conjunction with SI prefixes, SI prefix
symbols, names of units or symbols for units. . 26
5.4.4 Restrictions on combining SI prefixes, SI prefix symbols, names of
units and symbols for units . 26
5.5 Selecting SI prefixes and SI prefix symbols . 26
6 Data sources of units . 26
7 Identification of units . 27
Annex A (informative) Information about units . 28
Annex B (normative) Identifiers for units and quantities that are derived from the SI
system of units . 29
Annex C (normative) Identifiers for units and quantities that are not derived from the
SI system of units . 127
Annex D (normative) Identifiers for unit systems . 163
Annex E (informative) XML representation of units . 164
Bibliography . 260

Figure 1 – Overview about the relationships between the tables contained in the
annexes . 23
Figure 2 – International registration data identifier (IRDI), Source: ISO 11179-6:2005 . 27
Figure B.1 – Structure of table headers. 29
Figure C.1 – Structure of table headers . 127

Table 1 – Concepts for quantities. 16
Table 2 – Base quantity and base unit . 17
Table 3 – Base quantities . 19
Table 4 – Base quantities and base units in the International System of Units . 22
Table 5 – Representation of base quantities in the International System of Units [34] . 22

TS 62720  IEC:2013 – 3 –
Table 6 – Formation of multiples and factors of units to the base of 10 . 24
Table 7 – Formation of multiples of units to the base of 2 . 25
Table 8 – Units that are used without prefixes or prefix symbols . 26
Table B.1 – Absorbed dose . 29
Table B.2 – Absorbed dose rate . 30
Table B.3 – Acceleration . 30
Table B.4 – Active power . 31
Table B.5 – Amount of substance . 32
Table B.6 – Amount of substance concentration. 32
Table B.7 – Angular acceleration . 33
Table B.8 – Angular cross-section . 33
Table B.9 – Angular momentum . 33
Table B.10 – Angular velocity . 34
Table B.11 – Angular wave number . 34
Table B.12 – Apparent power . 34
Table B.13 – Areic bit density . 35
Table B.14 – Areic charge density . 35
Table B.15 – Areic mass . 36
Table B.16 – Avogadro constant . 36
Table B.17 – Bandwidth distance product . 36
Table B.18 – Battery capacity . 37
Table B.19 – Bit rate . 37
Table B.20 – Burst factor . 37
Table B.21 – Byte rate . 38
Table B.22 – Capacitance . 38
Table B.23 – Catalytic activity . 39
Table B.24 – Catalytic activity concentration . 39
Table B.25 – Celsius temperature . 40
Table B.26 – Compressibility . 40
Table B.27 – Conductivity . 40
Table B.28 – Cross-section . 41
Table B.29 – Dataset of bits . 41
Table B.30 – Dataset of bytes . 42
Table B.31 – Density . 42
Table B.32 – Density of states . 43
Table B.33 – Diffusion constant, thermal diffusivity . 43
Table B.34 – Digit rate . 43
Table B.35 – Dose equivalent . 44
Table B.36 – Dose equivalent rate . 44
Table B.37 – Dynamic viscosity . 45
Table B.38 – Einstein coefficients . 45
Table B.39 – Electric charge . 46
Table B.40 – Electrical conductance . 46

– 4 – TS 62720  IEC:2013
Table B.41 – Electric current . 47
Table B.42 – Electric current density . 48
Table B.43 – Electric dipole moment . 48
Table B.44 – Electric field strength . 49
Table B.45 – Electric flux density . 49
Table B.46 – Electric polarization . 50
Table B.47 – Electric resistance . 50
Table B.48 – Energy content . 51
Table B.49 – Energy density . 51
Table B.50 – Equilibrium constant based on concentration . 52
Table B.51 – Equilibrium constant based on pressure . 52
Table B.52 – Exposure rate . 52
Table B.53 – Failure rate . 53
Table B.54 – Faraday constant . 53
Table B.55 – First radiation constant. 53
Table B.56 – Force . 54
Table B.57 – Force constant . 54
Table B.58 – Frequency . 55
Table B.59 – Gas leak rate . 55
Table B.60 – Gradient . 55
Table B.61 – Gravitational constant . 56
Table B.62 – Hall coefficient . 56
Table B.63 – I²t-value, Joule integral . 56
Table B.64 – Illumination . 57
Table B.65 – Impulse . 57
Table B.66 – Incidence . 57
Table B.67 – Inductance . 58
Table B.68 – Information content . 58
Table B.69 – Ionic strength . 59
Table B.70 – Irradiance. 59
Table B.71 – Josephson constant . 59
Table B.72 – Kinematic viscosity . 60
Table B.73 – Kinetic energy . 60
Table B.74 – Length . 61
Table B.75 – Linear expansion coefficient . 61
Table B.76 – Lineic bit density . 61
Table B.77 – Lineic electric charge, linear electric charge density . 62
Table B.78 – Lineic electric current, linear electric current density . 62
Table B.79 – Lineic force . 63
Table B.80 – Lineic logarithmic ratio, linear attenuation, linear loss . 64
Table B.81 – Lineic mass . 64
Table B.82 – Lineic power. 65
Table B.83 – Lineic resistance . 66

TS 62720  IEC:2013 – 5 –
Table B.84 – Lineic torque . 67
Table B.85 – Logarithmic frequency interval . 67
Table B.86 – Logarithmic frequency interval to base 10 . 67
Table B.87 – Logarithmic ratio to base 10 . 68
Table B.88 – Logarithmic ratio to base e . 68
Table B.89 – Lorenz coefficient . 68
Table B.90 – Loudness . 69
Table B.91 – Loudness level . 69
Table B.92 – Luminance . 69
Table B.93 – Luminous efficacy . 70
Table B.94 – Luminous exitance . 70
Table B.95 – Luminous exposure . 70
Table B.96 – Luminous flux . 71
Table B.97 – Luminous intensity . 71
Table B.98 – Magnetic dipole moment . 71
Table B.99 – Magnetic dipole moment of a molecule . 72
Table B.100 – Magnetic field strength, magnetizing field strength . 72
Table B.101 – Magnetic flux . 73
Table B.102 – Magnetic flux density. 73
Table B.103 – Magnetic moment . 73
Table B.104 – Magnetic polarization . 74
Table B.105 – Magnetic vector potential . 74
Table B.106 – Mass . 75
Table B.107 – Mass attenuation coefficient . 75
Table B.108 – Mass density . 76
Table B.109 – Mass flow rate . 77
Table B.110 – Mass flux density . 77
Table B.111 – Mass ratio . 78
Table B.112 – Massic activity, specific activity . 78
Table B.113 – Massic electric current . 79
Table B.114 – Massic heat capacity, specific heat capacity. 79
Table B.115 – Massic power, specific power . 80
Table B.116 – Massic torque. 80
Table B.117 – Mechanical impedance . 80
Table B.118 – Median information flow, expressed as a binary logarithm . 81
Table B.119 – Median information flow, expressed as a common logarithm . 81
Table B.120 – Median information flow, expressed as a natural logarithm . 81
Table B.121 – Mobility . 81
Table B.122 – Molar attenuation coefficient . 82
Table B.123 – Molar conductivity . 82
Table B.124 – Molar flow rate . 82
Table B.125 – Molar heat capacitiy . 83
Table B.126 – Molar internal energy . 83

– 6 – TS 62720  IEC:2013
Table B.127 – Molar mass . 83
Table B.128 – Molar optical rotatory power . 83
Table B.129 – Molar volume . 84
Table B.130 – Moment of inertia . 84
Table B.131 – Motor constant . 84
Table B.132 – Mass stopping power, atomic stopping power . 85
Table B.133 – Nuclear energy . 85
Table B.134 – Particle current density . 85
Table B.135 – Particle fluence . 85
Table B.136 – Permeability . 86
Table B.137 – Permeance . 86
Table B.138 – Permittivity . 87
Table B.139 – Photon intensity . 87
Table B.140 – Photon luminance . 87
Table B.141 – Planck's constant . 88
Table B.142 – Plane angle . 88
Table B.143 – Polarizability . 88
Table B.144 – Pressure . 89
Table B.145 – Pressure coefficient . 89
Table B.146 – Pressure gradient . 90
Table B.147 – Pressure in relation to volume flow rate . 90
Table B.148 – Quantity . 90
Table B.149 – Quantity of light . 90
Table B.150 – Radiance, total radiance. 91
Table B.151 – Radiant energy exposure . 91
Table B.152 – Radiant exposure . 91
Table B.153 – Radiant intensity . 91
Table B.154 – Radioactive decay . 92
Table B.155 – Rate of rise of voltage . 92
Table B.156 – Ratio . 93
Table B.157 – Reactive power . 93
Table B.158 – Reciprocal energy . 94
Table B.159 – Reciprocal mass. 94
Table B.160 – Reciprocal voltage . 95
Table B.161 – Reluctance . 95
Table B.162 – Repetency . 95
Table B.163 – Resistivity . 96
Table B.164 – Richardson constant . 96
Table B.165 – Rotary-translatory motion conversion . 96
Table B.166 – Scalar magnetic potential . 97
Table B.167 – Second moment of area (axial) . 97
Table B.168 – Second moment of area (polar) . 97
Table B.169 – Second radiation constant . 98

TS 62720  IEC:2013 – 7 –
Table B.170 – Section modulus. 98
Table B.171 – Seebeck coefficient . 98
Table B.172 – Slowing-down density . 99
Table B.173 – Solid angle . 99
Table B.174 – Sound exposure . 99
Table B.175 – Specific (internal) energy . 100
Table B.176 – Specific optical rotational ability . 100
Table B.177 – Specific volume . 101
Table B.178 – Spectral angular cross-section . 101
Table B.179 – Spectral cross-section . 101
Table B.180 – Spectral density of vibrational modes . 102
Table B.181 – Spectral radiant energy density in terms of wavelength . 102
Table B.182 – State density as expression of angular frequency . 102
Table B.183 – Stefan-Boltzmann constant . 103
Table B.184 – Surface . 103
Table B.185 – Surface-related volume flow rate . 103
Table B.186 – Surface tension . 104
Table B.187 – Surge impedance of the medium . 104
Table B.188 – Temperature change rate, rate of change of temperature . 105
Table B.189 – Thermal capacitance . 105
Table B.190 – Thermal coefficient of linear expansion . 105
Table B.191 – Thermal conductance . 106
Table B.192 – Thermal conductivity . 106
Table B.193 —Thermal energy. 106
Table B.194 – Thermal insulation . 107
Table B.195 – Thermal resistance . 107
Table B.196 – Thermal resistivity . 107
Table B.197 – Thermal transmittance . 107
Table B.198 – Thermodynamic temperature . 108
Table B.199 – Time. 108
Table B.200 – Time constant . 109
Table B.201 – Time-related logarithmic ratio . 109
Table B.202 – Torque . 109
Table B.203 – Torque constant . 110
Table B.204 – Torsional rigidity. 110
Table B.205 – Total linear stopping power . 110
Table B.206 – Total mass stopping power . 110
Table B.207 – Traffic intensity . 111
Table B.208 – Unbalance . 111
Table B.209 – Variation (due to modified position) . 111
Table B.210 – Variation (due to output load) . 111
Table B.211 – Variation of density (due to pressure) . 112
Table B.212 – Variation of dynamic viscosity (due to pressure) . 112

– 8 – TS 62720  IEC:2013
Table B.213 – Variation of dynamic viscosity (due to temperature) . 112
Table B.214 – Variation of electric current (due to pressure) . 112
Table B.215 – Variation of kinematic viscosity (due to pressure) . 113
Table B.216 – Variation of kinematic viscosity (due to temperature) . 113
Table B.217 – Variation of level (due to pressure) . 113
Table B.218 – Variation of level (due to temperature) . 113
Table B.219 – Variation of mass (due to pressure) . 114
Table B.220 – Variation of mass (due to temperature) . 114
Table B.221 – Variation of mass density (due to temperature) . 115
Table B.222 – Variation of mass flow rate (due to pressure) . 115
Table B.223 – Variation of mass flow rate (due to temperature) . 116
Table B.224 – Variation of molality (due to pressure) . 116
Table B.225 – Variation of molality (due to temperature) . 116
Table B.226 – Variation of molar concentration (due to pressure) . 116
Table B.227 – Variation of molar concentration (due to temperature) . 117
Table B.228 – Variation of pressure (due to pressure) . 117
Table B.229 – Variation of temperature (due to pressure) . 117
Table B.230 – Variation of temperature (due to temperature) . 117
Table B.231 – Variation of velocity (due to pressure) . 117
Table B.232 – Variation of velocity (due to temperature) . 118
Table B.233 – Variation of voltage (due to pressure). 118
Table B.234 – Variation of volume (due to pressure) . 118
Table B.235 – Variation of volume (due to temperature) . 118
Table B.236 – Variation of volume flow rate (due to pressure) . 119
Table B.237 – Variation of volume flow rate (due to temperature) . 119
Table B.238 – Velocity . 120
Table B.239 – Voltage . 121
Table B.240 – Volume. 122
Table B.241 – Volume flow rate . 123
Table B.242 – Volume fraction . 124
Table B.243 – Volumic bit density . 124
Table B.244 – Volumic electric charge, electric charge density . 125
Table B.245 – Volumic output power . 125
Table B.246 – Water vapour permeability. 126
Table C.1 – Absolute typographic measurement . 128
Table C.2 – Acceleration . 128
Table C.3 – Active power . 129
Table C.4 – Amount of substance . 129
Table C.5 – Angular velocity . 129
Table C.6 – Areic mass . 130
Table C.7 – Amount of biologically active substance . 130
Table C.8 – Catalytic activity. 130
Table C.9 – Catalytic activity concentration . 130

TS 62720  IEC:2013 – 9 –
Table C.10 – Compressibility . 130
Table C.11 – Density . 130
Table C.12 – Diffusion constant . 131
Table C.13 – Dose equivalent . 131
Table C.14 – Dose equivalent rate . 131
Table C.15 – Dots per inch . 131
Table C.16 – Dynamic viscosity . 132
Table C.17 – Earthquake magnitude . 132
Table C.18 – Electric charge . 132
Table C.19 – Electric current . 132
Table C.20 – Electric field strength . 133
Table C.21 – Electrical conductance .
...

IEC/TS 62720 ®
Edition 1.0 2013-05
TECHNICAL
SPECIFICATION
SPÉCIFICATION
TECHNIQUE
Identification of units of measurement for computer-based processing

Identification des unités de mesure pour le traitement assisté par ordinateur

IEC/TS 62720:2013
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 IEC's 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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les
microfilms, sans l'accord écrit de la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
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.

Useful links:
IEC publications search - www.iec.ch/searchpub Electropedia - www.electropedia.org
The advanced search enables you to find IEC publications The world's leading online dictionary of electronic and
by a variety of criteria (reference number, text, technical electrical terms containing more than 30 000 terms and
committee,…). definitions in English and French, with equivalent terms in
It also gives information on projects, replaced and additional languages. Also known as the International
withdrawn publications. Electrotechnical Vocabulary (IEV) on-line.

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Stay up to date on all new IEC publications. Just Published If you wish to give us your feedback on this publication
details all new publications released. Available on-line and or need further assistance, please contact the
also once a month by email. Customer Service Centre: [e-mail].

A propos de la CEI
La Commission Electrotechnique Internationale (CEI) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.

Liens utiles:
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La recherche avancée vous permet de trouver des Le premier dictionnaire en ligne au monde de termes
publications CEI en utilisant différents critères (numéro de électroniques et électriques. Il contient plus de 30 000
référence, texte, comité d’études,…). termes et définitions en anglais et en français, ainsi que
Elle donne aussi des informations sur les projets et les les termes équivalents dans les langues additionnelles.
publications remplacées ou retirées. Egalement appelé Vocabulaire Electrotechnique
International (VEI) en ligne.
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Just Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur
Disponible en ligne et aussi une fois par mois par email. cette publication ou si vous avez des questions
contactez-nous: [e-mail].
IEC/TS 62720 ®
Edition 1.0 2013-05
TECHNICAL
SPECIFICATION
SPÉCIFICATION
TECHNIQUE
Identification of units of measurement for computer-based processing

Identification des unités de mesure pour le traitement assisté par ordinateur

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XH
ICS 01.060; 35.240.50 ISBN 978-2-83220-823-6

– 2 – TS 62720  IEC:2013
CONTENTS
FOREWORD . 12
INTRODUCTION . 14
1 Scope . 15
2 Normative references . 15
3 Terms and definitions . 15
4 Relations between quantities, units and their systems . 21
4.1 General . 21
4.2 The International System of Quantities and the International System of Units . 21
4.3 Other systems of quantities and units . 23
4.4 Context of units, quantities, and systems of units . 23
5 SI prefixes and SI prefix symbols. 24
5.1 General . 24
5.2 Formation of multiples and factors to the base of 10 . 24
5.3 Formation of multiples to the base of 2 . 25
5.4 Usage of SI prefixes and SI prefix symbols . 25
5.4.1 General . 25
5.4.2 Combination of SI prefixes, SI prefix symbols, names of units and
symbols for units . 25
5.4.3 Use of power exponentials in conjunction with SI prefixes, SI prefix
symbols, names of units or symbols for units. . 26
5.4.4 Restrictions on combining SI prefixes, SI prefix symbols, names of
units and symbols for units . 26
5.5 Selecting SI prefixes and SI prefix symbols . 26
6 Data sources of units . 26
7 Identification of units . 27
Annex A (informative) Information about units . 28
Annex B (normative) Identifiers for units and quantities that are derived from the SI
system of units . 29
Annex C (normative) Identifiers for units and quantities that are not derived from the
SI system of units . 127
Annex D (normative) Identifiers for unit systems . 163
Annex E (informative) XML representation of units . 164
Bibliography . 260

Figure 1 – Overview about the relationships between the tables contained in the
annexes . 23
Figure 2 – International registration data identifier (IRDI), Source: ISO 11179-6:2005 . 27
Figure B.1 – Structure of table headers. 29
Figure C.1 – Structure of table headers . 127

Table 1 – Concepts for quantities. 16
Table 2 – Base quantity and base unit . 17
Table 3 – Base quantities . 19
Table 4 – Base quantities and base units in the International System of Units . 22
Table 5 – Representation of base quantities in the International System of Units [34] . 22

TS 62720  IEC:2013 – 3 –
Table 6 – Formation of multiples and factors of units to the base of 10 . 24
Table 7 – Formation of multiples of units to the base of 2 . 25
Table 8 – Units that are used without prefixes or prefix symbols . 26
Table B.1 – Absorbed dose . 29
Table B.2 – Absorbed dose rate . 30
Table B.3 – Acceleration . 30
Table B.4 – Active power . 31
Table B.5 – Amount of substance . 32
Table B.6 – Amount of substance concentration. 32
Table B.7 – Angular acceleration . 33
Table B.8 – Angular cross-section . 33
Table B.9 – Angular momentum . 33
Table B.10 – Angular velocity . 34
Table B.11 – Angular wave number . 34
Table B.12 – Apparent power . 34
Table B.13 – Areic bit density . 35
Table B.14 – Areic charge density . 35
Table B.15 – Areic mass . 36
Table B.16 – Avogadro constant . 36
Table B.17 – Bandwidth distance product . 36
Table B.18 – Battery capacity . 37
Table B.19 – Bit rate . 37
Table B.20 – Burst factor . 37
Table B.21 – Byte rate . 38
Table B.22 – Capacitance . 38
Table B.23 – Catalytic activity . 39
Table B.24 – Catalytic activity concentration . 39
Table B.25 – Celsius temperature . 40
Table B.26 – Compressibility . 40
Table B.27 – Conductivity . 40
Table B.28 – Cross-section . 41
Table B.29 – Dataset of bits . 41
Table B.30 – Dataset of bytes . 42
Table B.31 – Density . 42
Table B.32 – Density of states . 43
Table B.33 – Diffusion constant, thermal diffusivity . 43
Table B.34 – Digit rate . 43
Table B.35 – Dose equivalent . 44
Table B.36 – Dose equivalent rate . 44
Table B.37 – Dynamic viscosity . 45
Table B.38 – Einstein coefficients . 45
Table B.39 – Electric charge . 46
Table B.40 – Electrical conductance . 46

– 4 – TS 62720  IEC:2013
Table B.41 – Electric current . 47
Table B.42 – Electric current density . 48
Table B.43 – Electric dipole moment . 48
Table B.44 – Electric field strength . 49
Table B.45 – Electric flux density . 49
Table B.46 – Electric polarization . 50
Table B.47 – Electric resistance . 50
Table B.48 – Energy content . 51
Table B.49 – Energy density . 51
Table B.50 – Equilibrium constant based on concentration . 52
Table B.51 – Equilibrium constant based on pressure . 52
Table B.52 – Exposure rate . 52
Table B.53 – Failure rate . 53
Table B.54 – Faraday constant . 53
Table B.55 – First radiation constant. 53
Table B.56 – Force . 54
Table B.57 – Force constant . 54
Table B.58 – Frequency . 55
Table B.59 – Gas leak rate . 55
Table B.60 – Gradient . 55
Table B.61 – Gravitational constant . 56
Table B.62 – Hall coefficient . 56
Table B.63 – I²t-value, Joule integral . 56
Table B.64 – Illumination . 57
Table B.65 – Impulse . 57
Table B.66 – Incidence . 57
Table B.67 – Inductance . 58
Table B.68 – Information content . 58
Table B.69 – Ionic strength . 59
Table B.70 – Irradiance. 59
Table B.71 – Josephson constant . 59
Table B.72 – Kinematic viscosity . 60
Table B.73 – Kinetic energy . 60
Table B.74 – Length . 61
Table B.75 – Linear expansion coefficient . 61
Table B.76 – Lineic bit density . 61
Table B.77 – Lineic electric charge, linear electric charge density . 62
Table B.78 – Lineic electric current, linear electric current density . 62
Table B.79 – Lineic force . 63
Table B.80 – Lineic logarithmic ratio, linear attenuation, linear loss . 64
Table B.81 – Lineic mass . 64
Table B.82 – Lineic power. 65
Table B.83 – Lineic resistance . 66

TS 62720  IEC:2013 – 5 –
Table B.84 – Lineic torque . 67
Table B.85 – Logarithmic frequency interval . 67
Table B.86 – Logarithmic frequency interval to base 10 . 67
Table B.87 – Logarithmic ratio to base 10 . 68
Table B.88 – Logarithmic ratio to base e . 68
Table B.89 – Lorenz coefficient . 68
Table B.90 – Loudness . 69
Table B.91 – Loudness level . 69
Table B.92 – Luminance . 69
Table B.93 – Luminous efficacy . 70
Table B.94 – Luminous exitance . 70
Table B.95 – Luminous exposure . 70
Table B.96 – Luminous flux . 71
Table B.97 – Luminous intensity . 71
Table B.98 – Magnetic dipole moment . 71
Table B.99 – Magnetic dipole moment of a molecule . 72
Table B.100 – Magnetic field strength, magnetizing field strength . 72
Table B.101 – Magnetic flux . 73
Table B.102 – Magnetic flux density. 73
Table B.103 – Magnetic moment . 73
Table B.104 – Magnetic polarization . 74
Table B.105 – Magnetic vector potential . 74
Table B.106 – Mass . 75
Table B.107 – Mass attenuation coefficient . 75
Table B.108 – Mass density . 76
Table B.109 – Mass flow rate . 77
Table B.110 – Mass flux density . 77
Table B.111 – Mass ratio . 78
Table B.112 – Massic activity, specific activity . 78
Table B.113 – Massic electric current . 79
Table B.114 – Massic heat capacity, specific heat capacity. 79
Table B.115 – Massic power, specific power . 80
Table B.116 – Massic torque. 80
Table B.117 – Mechanical impedance . 80
Table B.118 – Median information flow, expressed as a binary logarithm . 81
Table B.119 – Median information flow, expressed as a common logarithm . 81
Table B.120 – Median information flow, expressed as a natural logarithm . 81
Table B.121 – Mobility . 81
Table B.122 – Molar attenuation coefficient . 82
Table B.123 – Molar conductivity . 82
Table B.124 – Molar flow rate . 82
Table B.125 – Molar heat capacitiy . 83
Table B.126 – Molar internal energy . 83

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Table B.127 – Molar mass . 83
Table B.128 – Molar optical rotatory power . 83
Table B.129 – Molar volume . 84
Table B.130 – Moment of inertia . 84
Table B.131 – Motor constant . 84
Table B.132 – Mass stopping power, atomic stopping power . 85
Table B.133 – Nuclear energy . 85
Table B.134 – Particle current density . 85
Table B.135 – Particle fluence . 85
Table B.136 – Permeability . 86
Table B.137 – Permeance . 86
Table B.138 – Permittivity . 87
Table B.139 – Photon intensity . 87
Table B.140 – Photon luminance . 87
Table B.141 – Planck's constant . 88
Table B.142 – Plane angle . 88
Table B.143 – Polarizability . 88
Table B.144 – Pressure . 89
Table B.145 – Pressure coefficient . 89
Table B.146 – Pressure gradient . 90
Table B.147 – Pressure in relation to volume flow rate . 90
Table B.148 – Quantity . 90
Table B.149 – Quantity of light . 90
Table B.150 – Radiance, total radiance. 91
Table B.151 – Radiant energy exposure . 91
Table B.152 – Radiant exposure . 91
Table B.153 – Radiant intensity . 91
Table B.154 – Radioactive decay . 92
Table B.155 – Rate of rise of voltage . 92
Table B.156 – Ratio . 93
Table B.157 – Reactive power . 93
Table B.158 – Reciprocal energy . 94
Table B.159 – Reciprocal mass. 94
Table B.160 – Reciprocal voltage . 95
Table B.161 – Reluctance . 95
Table B.162 – Repetency . 95
Table B.163 – Resistivity . 96
Table B.164 – Richardson constant . 96
Table B.165 – Rotary-translatory motion conversion . 96
Table B.166 – Scalar magnetic potential . 97
Table B.167 – Second moment of area (axial) . 97
Table B.168 – Second moment of area (polar) . 97
Table B.169 – Second radiation constant . 98

TS 62720  IEC:2013 – 7 –
Table B.170 – Section modulus. 98
Table B.171 – Seebeck coefficient . 98
Table B.172 – Slowing-down density . 99
Table B.173 – Solid angle . 99
Table B.174 – Sound exposure . 99
Table B.175 – Specific (internal) energy . 100
Table B.176 – Specific optical rotational ability . 100
Table B.177 – Specific volume . 101
Table B.178 – Spectral angular cross-section . 101
Table B.179 – Spectral cross-section . 101
Table B.180 – Spectral density of vibrational modes . 102
Table B.181 – Spectral radiant energy density in terms of wavelength . 102
Table B.182 – State density as expression of angular frequency . 102
Table B.183 – Stefan-Boltzmann constant . 103
Table B.184 – Surface . 103
Table B.185 – Surface-related volume flow rate . 103
Table B.186 – Surface tension . 104
Table B.187 – Surge impedance of the medium . 104
Table B.188 – Temperature change rate, rate of change of temperature . 105
Table B.189 – Thermal capacitance . 105
Table B.190 – Thermal coefficient of linear expansion . 105
Table B.191 – Thermal conductance . 106
Table B.192 – Thermal conductivity . 106
Table B.193 —Thermal energy. 106
Table B.194 – Thermal insulation . 107
Table B.195 – Thermal resistance . 107
Table B.196 – Thermal resistivity . 107
Table B.197 – Thermal transmittance . 107
Table B.198 – Thermodynamic temperature . 108
Table B.199 – Time. 108
Table B.200 – Time constant . 109
Table B.201 – Time-related logarithmic ratio . 109
Table B.202 – Torque . 109
Table B.203 – Torque constant . 110
Table B.204 – Torsional rigidity. 110
Table B.205 – Total linear stopping power . 110
Table B.206 – Total mass stopping power . 110
Table B.207 – Traffic intensity . 111
Table B.208 – Unbalance . 111
Table B.209 – Variation (due to modified position) . 111
Table B.210 – Variation (due to output load) . 111
Table B.211 – Variation of density (due to pressure) . 112
Table B.212 – Variation of dynamic viscosity (due to pressure) . 112

– 8 – TS 62720  IEC:2013
Table B.213 – Variation of dynamic viscosity (due to temperature) . 112
Table B.214 – Variation of electric current (due to pressure) . 112
Table B.215 – Variation of kinematic viscosity (due to pressure) . 113
Table B.216 – Variation of kinematic viscosity (due to temperature) . 113
Table B.217 – Variation of level (due to pressure) . 113
Table B.218 – Variation of level (due to temperature) . 113
Table B.219 – Variation of mass (due to pressure) . 114
Table B.220 – Variation of mass (due to temperature) . 114
Table B.221 – Variation of mass density (due to temperature) . 115
Table B.222 – Variation of mass flow rate (due to pressure) . 115
Table B.223 – Variation of mass flow rate (due to temperature) . 116
Table B.224 – Variation of molality (due to pressure) . 116
Table B.225 – Variation of molality (due to temperature) . 116
Table B.226 – Variation of molar concentration (due to pressure) . 116
Table B.227 – Variation of molar concentration (due to temperature) . 117
Table B.228 – Variation of pressure (due to pressure) . 117
Table B.229 – Variation of temperature (due to pressure) . 117
Table B.230 – Variation of temperature (due to temperature) . 117
Table B.231 – Variation of velocity (due to pressure) . 117
Table B.232 – Variation of velocity (due to temperature) . 118
Table B.233 – Variation of voltage (due to pressure). 118
Table B.234 – Variation of volume (due to pressure) . 118
Table B.235 – Variation of volume (due to temperature) . 118
Table B.236 – Variation of volume flow rate (due to pressure) . 119
Table B.237 – Variation of volume flow rate (due to temperature) . 119
Table B.238 – Velocity . 120
Table B.239 – Voltage . 121
Table B.240 – Volume. 122
Table B.241 – Volume flow rate . 123
Table B.242 – Volume fraction . 124
Table B.243 – Volumic bit density . 124
Table B.244 – Volumic electric charge, electric charge density . 125
Table B.245 – Volumic output power . 125
Table B.246 – Water vapour permeability. 126
Table C.1 – Absolute typographic measurement . 128
Table C.2 – Acceleration . 128
Table C.3 – Active power . 129
Table C.4 – Amount of substance . 129
Table C.5 – Angular velocity . 129
Table C.6 – Areic mass . 130
Table C.7 – Amount of biologically active substance . 130
Table C.8 – Catalytic activity. 130
Table C.9 – Catalytic activity concentration . 130

TS 62720  IEC:2013 – 9 –
Table C.10 – Compressibility . 130
Table C.11 – Density . 130
Table C.12 – Diffusion constant . 131
Table C.13 – Dose equivalent . 131
Table C.14 – Dose equivalent rate . 131
Table C.15 – Dots per inch . 131
Table C.16 – Dynamic viscosity . 132
Table C.17 – Earthquake magnitude . 132
Table C.18 – Electric charge . 132
Table C.19 – Electric current . 132
Table C.20 – Electric field strength . 133
Table C.21 – Electrical conductance .
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