Abstract：The International System of Units (SI) is one of the greatest scientific, technological, and political achievements of recent times. After the formal introduction of the SI, it was necessary to accept the ongoing usage of some non-SI units because of their long history of previous use, despite this losing the benefit of coherence that the SI brings. This work reviews the history of non-SI units that have been allowed for use with the SI in successive SI Brochures, observes the rules that have been required for this use especially with SI prefixes, and notes that this set of non-SI units has decreased significantly as the SI has become more deeply embedded in modern society. The current situation, where a relatively small set of non-SI units remain accepted for use with the SI, is analyzed. It is observed that these non-SI units acquire quasi-SI status because of their listing in the SI Brochure. As a result, it is proposed that this set of non-SI units should be as small as possible and that clear rules for their use are necessary, most obviously with SI prefixes where the current guidance needs improvement. Historical precedent has been examined to assist in shaping these recommendations, which could be discussed and considered when the SI Brochure is next updated.
作者简介: 理查德·布朗(Richard J C Brown)是英国国家物理实验室(NPL)计量领域的负责人,他建议国际单位制(SI)引进ronna、quetta、ronto和quecto等4个词头,并于2022年11月被第27届国际计量大会(CGPM)采纳,现已生效。
Email:richard.brown@npl.co.uk
引用本文:
Richard J C Brown，译者 曹晶,任思源,于连超. 非国际单位制单位及其与国际单位制词头的结合使用[J]. 计量学报, 2024, 45(12): 1909-1916.
Richard J C Brown，译者 曹晶,任思源,于连超. Non-SI Units in the SI and their Use with SI Prefixes. Acta Metrologica Sinica, 2024, 45(12): 1909-1916.
International Bureau of Weights and Measures. Resolution 12 of the 11th CGPM[EB/OL]. www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12.
[13]
International Bureau of Weights and Measures. Previous editions of The International System of Units (SI)[EB/OL]. www. bipm. org/en/publications/si-brochure.
[6]
BROWN R J C. A further short history on the SI prefixes[J]. Metrologia, 2023, 60:013001.
raák D, Sedlák V, Snr E, et al.
[10]
ATKIN K. Units in astronomy: time for a clean sweep?[J]. Astronomy & Geophysics, 2018, 59(2): 32-33.
[2]
International Bureau of Weights and Measures. Comité International des Poids et Mesures Procès-Verbaux des Séances de 1879[EB/OL].Gauthier-Villars, 1880:41
[11]
GILBEY J D. SI units[J]. Anaesthesia & Intensive Care Medicine, 2023,24 :244-247.
[15]
International Astronomical Union. Resolutions adopted at the General Assemblies Resolution B2[EB/OL]. www.iau.org/static/resolutions/IAU2012_English.pdf.
[17]
FOSTER M P. The next 50 years of the SI: a review of the opportunities for the e-Science age[J]. Metrologia, 2010, 47: R41-R51.
[1]
La République Franaise 1795 Loi du 18 germinal an III relative aux poids et mesures[EB/OL]. Bulletin des Lois de la République Franaise 1er série, no. 135, texte no. 749:1-8
[8]
VERBERCK B. Note the knot[J]. Nature Physics, 2023, 19: 462.
[9]
VELYCHKO O, GORDIYENKO T. The use of metrological terms and SI units in environmental guides and international standards[J]. Measurement, 2007,40: 202-212.
[18]
National Institute of Standards and Technology. NIST Guide to the SI, Appendix B: Conversion Factors[EB/OL].www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors.
[5]
DE BOER J. Short History of the Prefixes[J]. Metrologia, 1966, 42(2): 165-166.
[7]
PRAK D, SEDLK V, SＬＮＬR E, et al. Changing the status of mmHg[J]. Accredit Qual Assur, 2020, 25: 81-82.
[14]
BROWN R J C. The unusual status of the hectare in the SI[J]. Metrologia, 2022, 59: 062101.
[16]
MILLS I M, TAYLOR B N, THOR A J. Definitions of the units radian, neper, beland decibel[J]. Metrologia, 2001,38:353-361.
[3]
BROWN R J C, MILTON M J T. Not just big numbers[J]. Nature Physics, 2023, 19: 144.
[12]
International Bureau of Weights and Measures. The International System of Units (SI), 9th edn[EB/OL]. BIPM, 2019.
2024, Vol. 45 
