Istoria kilogramului, prototip național aparținând României
The history of national prototype kilogram belonging to Romania

Summary/Abstract: The date of November 16, 2018 is considered a turning point for humanity, considering that on this day, in Versailles, a group of 60 countries signed for redefining four of the basic SI units (Kilogram, Kelvin, Ampere and Mole) depending on universal constants (the other three SI units were already defined). The new definitions of the four units entered into force on May 20, 2019, the same day that the World Metrology Day is celebrated. Even though the definition of the kilogram has been changed, at the moment, in many countries, the national standards of 1 kg of platinum-iridium are still used as a starting point in the expression of mass unit. In the first part of the current work, we describe the stages that led to the creation of the International Prototype Kilogram (Big K or IPK) and of the fourty platinum-iridium standards, after which we present the history of the National Prototype Kilogram No. 2 belonging to Romania – NPK – (from the moment of its creation until now).

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