 The International System of Units (SI), ninth edition, SI Brochure

ID: the-international-system-of-units-si-ninth-edition-si-brochure

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The International System of Units (SI), ninth edition, SI Brochure by

Codex  0 Created 2026-10-13 Updated 2026-10-18

Publisher: Bureau International des Poids et Mesures.

Online text: www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf

Cited passages: International Bureau of Weights and Measures, SI Brochure, ninth edition: section 2.2, printed pp. 123–125 (defining constants and alpha relation); section 2.3.1, printed p. 128 (ampere, epsilon0 and mu0); 26th CGPM Resolution 1, printed p. 194 (20 May 2019 effective date).

Online text: www.bipm.org/documents/d/guest/si-brochure-9-2_01

Additional inspected version: 4.01, June 2026; 2019 remains the original ninth-edition publication year. BIPM issues and hosts the brochure. Inspected locators: English §2.3.4, printed pp. 132–134, discussion and Table 4, notes (b), (c) and (g).

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