This is a list of units that are not defined as part of the
International System of Units
The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. E ...
(SI) but are otherwise mentioned in the SI Brochure,
Bureau international des poids et mesures
The International Bureau of Weights and Measures (french: Bureau international des poids et mesures, BIPM) is an intergovernmental organisation, through which its 59 member-states act together on measurement standards in four areas: chemistry ...
, "Non-SI units that are accepted for use with the SI", in
Le Système international d'unités (SI) / The International System of Units (SI), 9th ed.
(Sèvres: 2019), , c. 4, pp. 145–146. listed as being accepted for use alongside SI-units, or for explanatory purposes.
Units officially accepted for use with the SI
The SI prefixes can be used with several of these units, but not, for example, with the non-SI units of time.
Other units defined but not officially sanctioned
The following table lists units that are effectively defined in side- and footnotes in the 9th SI brochure. Units that are mentioned without a definition or that occur in historical material recorded in the appendices are not included.
Changes to units mentioned in the SI
With the publication of each edition of the SI brochure, the list of non-SI units listed in tables changed compared to the preceding SI brochures.
Bureau international des poids et mesures
The International Bureau of Weights and Measures (french: Bureau international des poids et mesures, BIPM) is an intergovernmental organisation, through which its 59 member-states act together on measurement standards in four areas: chemistry ...
Le Système international d'unités (SI) / The International System of Units (SI), 8th ed.
(Sèvres: Organisation Intergouvernementale de la Convention du Mètre, 2006‑05), . The table below compares the status of each unit for which the status has changed between editions of the SI Brochure.
In this table, the status descriptions have the following meanings:
* "accepted": The unit is accepted for use with the SI.
* "temporarily accepted": The unit is accepted for use with the SI, but is planned to be phased out.
* "listed": The unit is defined in a table of units in the brochure but not accepted for use with the SI.
* "footnote only": The unit is defined in a footnote or side note, without any mention in the main text.
* "not mentioned": There is no mention of the unit in the brochure, excluding historical appendices.
See also
*
International System of Quantities
*
International vocabulary of metrology
*
Metric prefix
*
SI base unit
The SI base units are the standard units of measurement defined by the International System of Units (SI) for the seven base quantities of what is now known as the International System of Quantities: they are notably a basic set from which all ...
*
SI derived unit
SI derived units are units of measurement derived from the
seven base units specified by the International System of Units (SI). They can be expressed as a product (or ratio) of one or more of the base units, possibly scaled by an appropriate po ...
Notes and references
Notes
References
{{DEFAULTSORT:Non-Si Units Accepted For Use With The Si
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