Marie Curie, the international radium standard and the BIPM

Abstract On 21 February 1913, a few decades before the International Bureau of Weights and Measures (BIPM) started to develop activities in field ionizing radiation, Marie Curie on behalf Radium Commission deposited first international radium standard at BIPM Sevres. From 1913 1935, was taken out for comparisons Laboratory Paris returned safe BIPM. This article describes how BIPM, established 1875 by Metre Convention, given role custodian time when mission maintain two fundamental units Metric System mainly directed toward measurements needed geodesy, standardization metric system establishment length mass standards. Through history second standards, we can oversee have evolved.