Redefinition of the International System of Units (SI) and Related Quantities in the Field of Ionizing Radiation

DOI Web Site PubMed
  • SAITO Norio
    NMIJ International Cooperation Office, National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST)

Bibliographic Information

Other Title
  • 国際単位系(SI)の定義改定と放射線関連量
  • 計測委員会企画 国際単位系(SI)の定義改定と放射線関連量
  • ケイソク イインカイ キカク コクサイ タンイケイ(SI)ノ テイギ カイテイ ト ホウシャセン カンレンリョウ

Search this article

Description

<p>The International System of Units (SI) is recommended for the practical system of units of measurement. The decision of redefining the seven base units of the SI (the second, the meter, the kilogram, the ampere, the kelvin, the mole and the candela) was made at the 26th meeting of the General Conference on Weights and Measures on 16 November 2018. This redefinition came into force starting 20 May 2019, and it became a big historic turning point for the metrology society. This is because the kilogram, the unit of mass, was defined only by an artifact as the international prototype of the kilogram, has been kept for 130 years since its determination in 1889, and was finally changed to the new definition by taking the fixed numerical value of the Planck constant on that day.</p><p>It is easily imagined that the redefinition of the SI base units has a strong impact on our daily life or the field of science. The reason why the SI redefinition had to be adapted is introduced firstly. Then, how the new definitions are applied now after a year from the redefinition and future prospective of the new definitions are discussed. In the last, the impacts of the SI redefinition in the field of the ionizing radiation, especially in the fields of the medical application of the ionizing radiation, are discussed.</p>

Journal

Keywords

Details 詳細情報について

Report a problem

Back to top