SI Brochure - TITLE

SI Brochure: The International System of Units (SI)

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The International System of Units
9th edition (2019)

Complete brochure (updated in 2026)

https://doi.org/10.59161/AUEZ1291
Le Système international d'unités
9e édition (2019)

Texte en français (mis à jour en 2026)

https://doi.org/10.59161/AUEZ1291
The International System of Units
9th edition (2019)

Text in English (updated in 2026)

https://doi.org/10.59161/AUEZ1291

SI Brochure citation

Citation: Bureau International des Poids et Mesures. (2026). Le Système international d'unités/The International System of Units [Brochure]. 9th edition. https://doi.org/10.59161/AUEZ1291

Appendices SI

Appendices

Please note that Appendices 1 and 4 are included in the text of the SI Brochure (see the documents above).

Appendices 2 and 3 below are available online only.

SI Appendix 2

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Appendix 3 – Units for photochemical and photobiological quantities
Annexe 3 – Unités pour la mesure des grandeurs photochimiques et photobiologiques

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Other files - TITLE

Additional files

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Concise Summary

(updated in 2026)
Résumé

(mis à jour en 2026)
Frequently Asked Questions

(updated in 2025)
Questions fréquentes

(mises à jour en 2025)

Previous editions - TITLE

Previous editions of the SI Brochure

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8th edition of the SI Brochure (2006)https://doi.org/10.59161/CCDJ5825
7th edition of the SI Brochure (1998)https://doi.org/10.59161/OJJZ7121
6th edition of the SI Brochure (1991)https://doi.org/10.59161/NYWK6447
5th edition of the SI Brochure (1985)https://doi.org/10.59161/PZAJ5870
4th edition of the SI Brochure (1981)https://doi.org/10.59161/CLUQ3699
3rd edition of the SI Brochure (1977)https://doi.org/10.59161/CASU6485
2nd edition of the SI Brochure (1973) https://doi.org/10.59161/JTBL2977
1st edition of the SI Brochure (1970)https://doi.org/10.59161/CDXH2109