The D.I. Mendeleyev Institute for Metrology (VNIIM) updated the State Primary Measurement Standard of Mass following the redefinition of the kilogram as a part of the redefinition of the SI base units.
Despite the limitations caused by the COVID-19 pandemic, our specialists conducted a number of studies that confirmed compliance of the mass standard characteristics with the hereto achieved at the international level.
The scientist-custodian of the mass standard, Yuri Kamenskih, notes that due to this improvement, the uncertainty in the unit transfer became 10 times smaller: from 6 ∙ 10-9 kg to 6 ∙ 10-10 kg, vacuum weighing technology was mastered, and accuracy of measurements in the sub-milligram range was achieved. Those improvements are essential for calibration of microbalances with an uncertainty less than 1 mg widely used in the pharmaceutical and chemical industries, and in the ongoing environmental research. The upgrade of our primary mass standard now enables Russia to participate in new international comparisons and provides a basis for declaration of new calibration and measurement capabilities.
Further important improvements will be needed, as soon as a domestic watt-balance is developed to conform to the newly adopted definition of the kilogram based on the fixed Plank constant instead of the platinum-iridium artifact.