View source for ISO/IEC 80000

{{Short description|Published ISO standard series}}
{{use dmy dates|date=March 2021}}
'''ISO 80000''' or '''IEC 80000''', '''''Quantities and units''''', is an [[international standard]] describing the [[International System of Quantities]] (ISQ). 
It was developed and promulgated jointly by the [[International Organization for Standardization]] (ISO) and the [[International Electrotechnical Commission]] (IEC).
It serves as a style guide for using [[physical quantities]] and [[Unit of measurement|units of measurement]], formulas involving them, and their corresponding units, in scientific and educational documents for worldwide use.
The ISO/IEC 80000 family of standards was completed with the publication of the first edition of Part 1 in November 2009.<ref>[http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=46202 Standards Catalogue TC/12 Quantities and Units]</ref><ref>{{Cite web |last=Schirn |first=Alexandra |date=2023-01-09 |title=ISO 80000-1:2022- Quantities And Units - ANSI Blog |url=https://blog.ansi.org/iso-80000-1-2022-quantities-and-units/ |access-date=2023-05-16 |website=The ANSI Blog |language=en-US}}</ref>

== Overview ==
By 2021, ISO/IEC 80000 comprised 13 parts, two of which (parts 6 and 13) were developed by IEC and the remaining 11 were developed by ISO, with a further three parts (15, 16 and 17) under development. Part 14 was withdrawn.
{| class="wikitable"
|-
!Part
!Year
!Name
!Replaces
!Status
|-
|ISO 80000-1<ref name=80000-1:2022>{{cite web|title=ISO 80000-1:2022|url=https://www.iso.org/standard/76921.html|publisher=[[International Organization for Standardization]]|access-date=2023-11-02}}</ref>
|2022
|General
|[[ISO 31-0]], [[IEC 60027|IEC 60027-1]] and [[IEC 60027|IEC 60027-3]]
|published
|-
|ISO 80000-2<ref name=80000-2:2019>{{cite web|title=ISO 80000-2:2019|url=https://www.iso.org/standard/64973.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
|2019
|[[Mathematics]]
|[[ISO 31-11]], [[IEC 60027|IEC 60027-1]]
|published
|-
|ISO 80000-3<ref name=80000-3:2019>{{cite web|title=ISO 80000-3:2019|url=https://www.iso.org/standard/64974.html|publisher=[[International Organization for Standardization]]|access-date=2019-10-23}}</ref>
|2019
|[[Space]] and [[time]]
|[[ISO 31-1]] and ISO 31-2
|published
|-
|ISO 80000-4<ref name=80000-4:2019>{{cite web|title=ISO 80000-4:2019|url=https://www.iso.org/standard/64975.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
|2019
|[[Mechanics]]
|[[ISO 31-3]]
|published
|-
|ISO 80000-5<ref name=80000-5:2019>{{cite web|title=ISO 80000-5:2019|url=https://www.iso.org/standard/64976.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
|2019
|[[Thermodynamics]]
|[[ISO 31-4]]
|published
|-
|IEC 80000-6<ref name=80000-6:2022>{{cite web|title=IEC 80000-6:2022|url=https://www.iso.org/standard/77846.html|publisher=[[International Organization for Standardization]]|access-date=2022-11-20}}</ref>
|2022
|[[Electromagnetism]]
|[[ISO 31-5]]
|published
|-
|ISO 80000-7<ref name=80000-7:2019>{{cite web|title=ISO 80000-7:2019|url=https://www.iso.org/standard/64977.html|publisher=[[International Organization for Standardization]]|access-date=2019-10-23}}</ref>
|2019
|[[Light]] and [[radiation]]
|[[ISO 31-6]]
|published
|-
|ISO 80000-8<ref>{{cite web|title=ISO 80000-8:2020|url=https://www.iso.org/standard/64978.html|publisher=[[International Organization for Standardization]]|access-date=2020-03-20}}</ref>
|2020
|[[Acoustics]]
|[[ISO 31-7]]
|published
|-
|ISO 80000-9<ref>{{cite web|title=ISO 80000-9:2019|url=https://www.iso.org/standard/64979.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
|2019
|[[Physical chemistry]] and [[molecular physics]]
|[[ISO 31-8]]
|published
|-
|ISO 80000-10<ref>{{cite web|title=ISO 80000-10:2019|url=https://www.iso.org/standard/64980.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
|2019
|[[Atomic physics|Atomic]] and [[nuclear physics]]
|[[ISO 31-9]] and [[ISO 31-10]]
|published
|-
|ISO 80000-11<ref>{{cite web|title=ISO 80000-11:2019|url=https://www.iso.org/standard/64982.html|publisher=[[International Organization for Standardization]]|access-date=2020-02-11}}</ref>
|2019
|[[Characteristic number (fluid dynamics)|Characteristic numbers]]
|[[ISO 31-12]]
|published
|-
|ISO 80000-12<ref>{{cite web|title=ISO 80000-12:2019|url=https://www.iso.org/standard/63480.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
|2019
|[[Condensed matter physics]]
|[[ISO 31-13]]
|published
|-
|IEC 80000-13<ref name=80000-13:2008>{{cite web|title=IEC 80000-13:2008|url=https://www.iso.org/standard/31898.html|publisher=[[International Organization for Standardization]]|access-date=2020-04-24}}</ref>
|2008
|[[Information science]] and [[Information technology|technology]]
|subclauses 3.8 and 3.9 of [[IEC 60027#IEC 60027-2|IEC 60027-2:2005]]
|published
|-
|IEC 80000-14<ref>{{cite web|title=IEC 80000-14:2008|url=https://www.iso.org/standard/43012.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
|2008
|[[Biometrics|Telebiometrics]] related to human physiology
|[[IEC 60027|IEC 60027-7]]
|withdrawn
|-
|IEC 80000-15<ref>{{cite web|title=IEC/CD 80000-15|url=https://www.iso.org/standard/76692.html|publisher=[[International Organization for Standardization]]|access-date=2022-04-24}}</ref>
|
|[[Logarithmic scale|Logarithmic]] and related quantities
|
|under development
|-
|IEC 80000-16<ref>{{cite web|title=IEC/CD 80000-16|url=https://www.iso.org/standard/76693.html|publisher=[[International Organization for Standardization]]|access-date=2021-05-01}}</ref>
|
|Printing and writing rules
|
|under development
|-
|IEC 80000-17<ref>{{cite web|title=IEC/CD 80000-17|url=https://www.iso.org/standard/76694.html|publisher=[[International Organization for Standardization]]|access-date=2021-05-01}}</ref>
|
|Time dependency
|
|under development
|-
|}

== Subject areas ==
By 2021 the 80000 standard had 13 published parts.<ref>{{cite web|url=https://www.ee.co.za/article/international-standards-quantities-units-revision.html|title=International standards for quantities and units are under revision|date=2017-01-31|work=EE Publishers}}</ref><ref>{{cite web|title=Standards by ISO/TC 12 – Quantities and units|url=https://www.iso.org/committee/46202/x/catalogue/p/1/u/1/w/0/d/0|publisher=[[International Organization for Standardization]]|access-date=2020-04-24}}</ref>

=== Part 1: General ===
ISO 80000-1:2022 revised ISO 80000-1:2009, which replaced ISO 31-0:1992 and ISO 1000:1992.<ref name=80000-1:2009>{{cite web|title=ISO 80000-1:2009 Quantities and units – Part 1: General|url=https://www.iso.org/standard/30669.html#lifecycle|publisher=[[International Organization for Standardization]]|access-date=2023-11-02}}</ref>
This document gives general information and definitions concerning quantities, systems of quantities, units, quantity and unit symbols, and coherent unit systems, especially the International System of Quantities (ISQ).<ref name=80000-1:2022/>
The text of the informative sections of this document is publicly available.<ref name=80000-1:2022(en)>{{cite web|title=ISO 80000-1:2022(en) Quantities and units – Part 1: General|url=https://www.iso.org/obp/ui/en/#iso:std:iso:80000:-1:ed-2:v1:en|publisher=[[International Organization for Standardization]]|access-date=2023-11-02}}</ref><ref name=80000-1:2009(en)>{{cite web|title=ISO 80000-1:2009(en) Quantities and units – Part 1: General|url=https://www.iso.org/obp/ui/#iso:std:iso:80000:-1:ed-1:v1:en|publisher=[[International Organization for Standardization]]|access-date=2023-11-02}}</ref>

=== Part 2: Mathematics ===
ISO 80000-2:2019 revised ISO 80000-2:2009,<ref name=80000-2:2019/> which superseded [[ISO 31-11]].<ref>{{cite web|title=ISO 80000-2:2009|url=https://www.iso.org/standard/31887.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
It specifies mathematical symbols, explains their meanings, and gives verbal equivalents and applications. The text of the informative sections of this document is publicly available.<ref>{{cite web|title=ISO 80000-2:2019(en) Quantities and units – Part 2: Mathematics|url=https://www.iso.org/obp/ui/#iso:std:iso:80000:-2:ed-2:v2:en|publisher=[[International Organization for Standardization]]|access-date=2019-10-23}}</ref>

=== Part 3: Space and time ===
ISO 80000-3:2019 revised ISO 80000-3:2006,<ref name=80000-3:2019/> which supersedes [[ISO 31-1]] and [[ISO 31-2]].<ref>{{cite web|title=ISO 80000-3:2006|url=http://www.iso.org/iso/catalogue_detail?csnumber=31888|publisher=[[International Organization for Standardization]]|access-date=2013-07-20}}</ref>
It gives names, symbols, definitions and units for quantities of space and time.
The text of this document is publicly available.<ref>{{cite web|title=ISO 80000-3:2019(en) Quantities and units – Part 3: Space and time|url=https://www.iso.org/obp/ui/#iso:std:iso:80000:-3:ed-2:v1:en|publisher=[[International Organization for Standardization]]|access-date=2019-10-23}}</ref> 

A definition of the [[decibel]], included in the original 2006 publication, was omitted in the 2019 revision, leaving ISO/IEC 80000 without a definition of this unit; a new part of the standard, IEC 80000-15 (Logarithmic and related quantities), is under development.

=== Part 4: Mechanics ===
ISO 80000-4:2019 revised ISO 80000-4:2006,<ref name=80000-4:2019/> which superseded [[ISO 31-3]].<ref>{{cite web|title=ISO 80000-4:2006|url=https://www.iso.org/standard/31889.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
It gives names, symbols, definitions and units for quantities of mechanics.
The text of this document is publicly available.<ref>{{cite web|title=ISO 80000-4:2019 Quantities and units – Part 4: Mechanics|url=https://www.iso.org/obp/ui/#iso:std:iso:80000:-4:ed-2:v1:en|publisher=[[International Organization for Standardization]]|access-date=2019-10-23}}</ref>

=== Part 5: Thermodynamics ===
ISO 80000-5:2019 revised ISO 80000-5:2007,<ref name=80000-5:2019/> which superseded [[ISO 31-4]].<ref>{{cite web|title=ISO 80000-5:2007|url=https://www.iso.org/standard/31890.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
It gives names, symbols, definitions and units for quantities of [[thermodynamics]].
The text of this document is publicly available.<ref>{{cite web|title=ISO 80000-5:2019(en) Quantities and units – Part 5: Thermodynamics|url=https://www.iso.org/obp/ui/#iso:std:iso:80000:-5:ed-2:v1:en|publisher=[[International Organization for Standardization]]|access-date=2019-10-23}}</ref>

=== Part 6: Electromagnetism ===
IEC 80000-6:2022 revised IEC 80000-6:2008,<ref name=80000-6:2022/> which superseded [[ISO 31-5]]<ref name=80000-6:2008>{{cite web|title=IEC 80000-6:2008|url=https://www.iso.org/standard/31891.html|publisher=[[International Organization for Standardization]]|access-date=2022-11-20}}</ref> as well as IEC 60027-1.
It gives names, symbols, and definitions for quantities and units of [[electromagnetism]].
The text of the informative sections of this document is publicly available.<ref>{{cite web|title=ISO 80000-6:2022(en,fr) Quantities and units – Part 6: Electromagnetism|url=https://www.iso.org/obp/ui/#iso:std:iec:80000:-6:ed-2:v1:en,fr|publisher=[[International Organization for Standardization]]|access-date=2022-11-21}}</ref>

=== Part 7: Light and radiation ===
ISO 80000-7:2019 revised ISO 80000-7:2008,<ref name=80000-7:2019/> which superseded [[ISO 31-6]].<ref>{{cite web|title=ISO 80000-7:2008|url=https://www.iso.org/standard/31892.html|publisher=[[International Organization for Standardization]]|access-date=2019-09-15}}</ref>
It gives names, symbols, definitions and units for quantities used for [[light]] and [[optical radiation]] in the [[wavelength]] range of approximately 1&nbsp;nm to 1&nbsp;mm.
The text of this document is publicly available.<ref>{{cite web|title=ISO 80000-7:2019(en) Quantities and units – Quantities and units — Part 7: Light and radiation|url=https://www.iso.org/obp/ui/#iso:std:iso:80000:-7:ed-2:v1:en|publisher=[[International Organization for Standardization]]|access-date=2021-03-25}}</ref>

=== Part 8: Acoustics ===
ISO 80000-8:2020 revised ISO 80000-8:2007,<ref>{{cite web|title=ISO 80000-8:2007|url=https://www.iso.org/standard/40669.html|publisher=[[International Organization for Standardization]]|access-date=2020-04-23}}</ref> which revised ISO 31-7:1992.<ref>{{cite web|title=ISO 31-7:1992|url=https://www.iso.org/standard/3641.html|publisher=[[International Organization for Standardization]]|access-date=2020-04-23}}</ref>
It gives names, symbols, definitions and units for quantities of [[acoustics]]. The text of the informative sections of this document are publicly available.<ref>{{cite web|title=ISO 80000-8:2020(en) Quantities and units – Part 8: Acoustics|url=https://www.iso.org/obp/ui/#iso:std:iso:80000:-8:ed-2:v1:en|publisher=[[International Organization for Standardization]]|access-date=2020-04-23}}</ref>

It has a foreword, scope introduction, scope, normative references (of which there are none), as well as terms and definitions. It includes definitions of [[sound pressure]], [[sound power]] and [[sound exposure]], and their corresponding [[level (logarithmic quantity)|levels]]: [[sound pressure level]], [[sound power level]] and [[sound exposure level]].  It includes definitions of the following quantities:
* logarithmic frequency range
* [[static pressure]]
* [[sound pressure]]
* [[Particle displacement|sound particle displacement]]
* [[Particle velocity|sound particle velocity]]
* [[Particle acceleration|sound particle acceleration]]
* [[Volumetric flow rate|volume flow rate]], [[volume velocity]]
* [[sound energy density]]
* [[sound energy]]
* [[sound power]]
* [[sound intensity]]
* [[sound exposure]]
* characteristic impedance for [[Longitudinal wave|longitudinal waves]]
* [[acoustic impedance]]
* [[sound pressure level]]
* [[sound power level]]
* [[sound exposure level]]
* [[reverberation time]]

=== Part 13: Information science and technology ===

IEC 80000-13:2008 was reviewed and confirmed in 2022 and published in 2008, and replaced subclauses 3.8 and 3.9 of IEC 60027-2:2005 and [[IEC 60027-3]].<ref name=80000-13:2008/>
It defines quantities and units used in [[information science]] and [[information technology]], and specifies names and symbols for these quantities and units. It has a scope; normative references; names, definitions and symbols; and prefixes for [[Binary number|binary]] multiples.

Quantities defined in this standard are:
* [[traffic intensity]] [''A'']: ''number of simultaneously busy resources in a particular pool of resources''
* traffic offered intensity [''A''<sub>0</sub>]: ''traffic intensity ... of the traffic that would have been generated by the users of a pool of resources if their use had not been limited by the size of the pool''
* traffic carried intensity [''Y'']: ''traffic intensity ... of the traffic served by a particular pool of resources''
* mean queue length [''L'', (''Ω'')]: time average of queue length
* loss probability [''B'']: ''probability for losing a call attempt''
* waiting probability [''W'']: ''probability for waiting for a resource''
* call intensity, calling rate [''λ'']: ''number of call attempts over a specified time interval divided by the duration of this interval''
* completed call intensity [''μ'']: ''call intensity ... for the call attempts that result in the transmission of an answer [[signal]]''
* [[Computer data storage|storage capacity]], storage size [''M'']
* equivalent binary storage capacity [''M''<sub>e</sub>]
* transfer rate [''r'', (''ν'')]
* period of data elements  [''T'']
* [[Bit|binary digit]] rate, bit rate [''r''<sub>b</sub>, ''r''<sub>bit</sub> (''ν''<sub>b</sub>, ''ν''<sub>bit</sub>)]
* period of [[Bit|binary digits]], bit period [''T''<sub>b</sub>, ''T''<sub>bit</sub>]
* equivalent binary digit rate, equivalent bit rate [''r''<sub>e</sub>, (''ν''<sub>e</sub>)]
* [[modulation rate]], line digit rate [''r''<sub>m</sub>, ''u'']
* quantizing distortion power [''T''<sub>Q</sub>]
* carrier powe<nowiki/>r [''P''<sub>c</sub>, ''C'']
* signal energy per binary digit [''E''<sub>b</sub>, ''E''<sub>bit</sub>]
* error probability [''P'']
* [[Hamming distance]] [''d''<sub>n</sub>]
* [[Clock rate|clock frequency]], clock rate [''f''<sub>cl</sub>]
* decision content [''D''<sub>a</sub>]
* [[information content]] [''I''(''x'')]
* [[Entropy (information theory)|entropy]] [''H'']
* [[Maximum Entropy|maximum entropy]] [''H''<sub>0</sub>, (''H''<sub>max</sub>)]
* [[relative entropy]] [''H''<sub>r</sub>]
* [[Redundancy theory of truth|redundancy]] [''R'']
* relative redundancy [''r'']
* joint information content [''I''(''x'', ''y'')]
* conditional information content [''I''(''x''|''y'')]
* [[conditional entropy]], mean conditional information content, average conditional information content [''H''(''X''|''Y'')]
* [[Equivocation (information theory)|equivocation]] [''H''(''X''∣''Y'')]
* [[Relevance|irrelevance]] [''C'']
* transinformation content [''T''(''x'', ''y'')]
* mean transinformation content [''T'']
* character mean entropy [''H''′]
* [[Information rate|average information rate]] [''H''*]
* character mean transinformation content [''T''′]
* average transinformation rate [''T''*]
* channel capacity per character; [[channel capacity]] [''C''′]
* channel time capacity; channel capacity [''C''*]

The Standard also includes definitions for units relating to information technology, such as the [[erlang (unit)|erlang]] (E), [[bit]] (bit), [[Octet (unit)|octet]] (o), [[byte]] (B), [[baud]] (Bd), [[shannon (unit)|shannon]] (Sh), [[hartley (unit)|hartley]] (Hart) and the [[nat (unit)|natural unit of information]] (nat).

Clause 4 of the Standard defines standard [[binary prefix]]es used to denote powers of 1024 as 1024<sup>1</sup> ([[kibi-]]), 1024<sup>2</sup> ([[mebi-]]), 1024<sup>3</sup> ([[gibi-]]), 1024<sup>4</sup> ([[tebi-]]), 1024<sup>5</sup> ([[pebi-]]), 1024<sup>6</sup> ([[exbi-]]), 1024<sup>7</sup> ([[zebi-]]) and 1024<sup>8</sup> ([[yobi-]]).

==International System of Quantities==
{{main|International System of Quantities}}
Part 1 of ISO 80000 introduces the International System of Quantities and describes its relationship with the [[International System of Units]] (SI).  Specifically, its introduction states "The system of quantities, including the relations among the quantities used as the basis of the units of the SI, is named the ''International System of Quantities'', denoted 'ISQ', in all languages."  It further clarifies that "ISQ is simply a convenient notation to assign to the essentially infinite and continually evolving and expanding system of quantities and equations on which all of modern science and technology rests.  ISQ is a shorthand notation for the 'system of quantities on which the SI is based'."

==Units of the ISO and IEC 80000 series==
The standard includes all SI units but is not limited to only SI units. Units that form part of the standard but not the SI include the units of information storage ([[bit]] and [[byte]]), units of [[Entropy (information theory)|entropy]] ([[shannon (unit)|shannon]], [[nat (unit)|natural unit of information]] and [[hartley (unit)|hartley]]), and the [[Erlang (unit)|erlang]] (a unit of traffic intensity). 

The standard includes all [[SI prefix]]es as well as the [[binary prefix]]es kibi-, mebi-, gibi-, etc., originally introduced by the [[IEC 60027-2|International Electrotechnical Commission]] to standardise binary multiples of byte such as [[mebibyte]] (MiB), for {{val|1024}}<sup>2</sup> bytes, to distinguish them from their decimal counterparts such as [[megabyte]] (MB), for precisely one million ({{val|1000}}<sup>2</sup>) bytes. In the standard, the application of the binary prefixes is not limited to units of information storage. For example, a frequency ten [[Octave (electronics)|octaves]] above one hertz, i.e., 2<sup>10</sup> Hz ({{val|1024|u=Hz}}), is one kibihertz (1 KiHz).<ref>{{cite journal |date=January 2022 |orig-date=2021-11-09 |title=A terminology standard for underwater acoustics and the benefits of international standardization. |url=https://ieeexplore.ieee.org/document/9607022 |journal=[[IEEE Journal of Oceanic Engineering]] |publisher=[[IEEE]] |volume=47 |issue=1 |pages=179–200 |doi=10.1109/JOE.2021.3085947 |issn=0364-9059 |eissn=1558-1691 |s2cid=243948953 |access-date=2022-12-20 |author-last1=Ainslie |author-first1=Michael A. |author-last2=Halvorsen |author-first2=Michele B. |author-last3=Robinson |author-first3=Stephen P.|bibcode=2022IJOE...47..179A |doi-access=free }} [https://web.archive.org/web/20221220112042/https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9607022] (22 pages)</ref> These [[binary prefix]]es were standardized first in a 1999 addendum to [[IEC 60027|IEC 60027-2]].
The harmonized IEC 80000-13:2008 standard cancels and replaces subclauses 3.8 and 3.9 of IEC 60027-2:2005, which had defined the prefixes for binary multiples. The only significant change in IEC 80000-13 is the addition of explicit definitions for some quantities.

==See also==
* [[International vocabulary of metrology|International Vocabulary of Metrology]]
* [[SI|International System of Units]]
* [[BIPM]]&nbsp;– publishes freely available information on SI units
* [[NIST]]&nbsp;– official U.S. representative for SI; publishes freely available guide to use of SI

==References==
{{reflist}}

== External links ==
* [https://www.bipm.org/en/publications/si-brochure BIPM SI Brochure]
* [http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_tc_browse.htm?commid=46202 ISO TC12 standards]&nbsp;– Quantities, units, symbols, conversion factors
* [http://physics.nist.gov/Pubs/SP330/contents.html NIST Special Publication 330]&nbsp;– The International System of Units
* [http://physics.nist.gov/Pubs/SP811/contents.html NIST Special Publication 811]&nbsp;– Guide for the Use of the International System  of Units

{{ISO standards}}
{{List of International Electrotechnical Commission standards}}

{{DEFAULTSORT:ISO IEC 80000}}
[[Category:ISO/IEC 80000| ]]
[[Category:Physical quantities|+]]
[[Category:Measurement]]
[[Category:ISO/IEC standards|#80000]]