Kalinin M.

As you know among seven main SI units the most vulnerable is kilogram since it’s a physical object made by humans and it can be destroyed or damaged. The definitions of ampere, mole, and candela depend on the kilogram definition. Over the past hundred years of comparisons the stability of the kilogram prototype nominal value in comparison to the national standards demonstrated their masses discrepancy by 50 μg. How this problem has been solved you will learn from the present article.