Reference standards-copies of mass unit: calibration 2020 using vacuum comparator CCL 1007

The article discusses the calibration results of reference standards-copies according to State Primary Standard Mass Unit using new CCL 1007 vacuum comparator and buoyancy artifacts. authors provided historical data on calibrations copies International Prototype Kilogram (IPK) starting from 1892, including Russian prototype № 12. instability kilogram No. 12 corresponds international values is assessed at 5 · 10 –11 kg per year. Changes in mass are relation IPK, but it impossible determine what extent has changed. This was reason for adoption a value kilogram. Following 26th meeting General Conference Weights Measures (CGPM) held Paris November 2018, Planck constant numerically established with absolute accuracy, total uncer tainty 1 –8 assigned IPK. Thus, set aim preserve numerical uncertainty by reducing transfer error times. presents six primary processing method least squares, budget provided. confirmed accuracy increase unit times range 6 –9 –10 use graduated 0.1 μg sorption artifacts direct measurements air density. made possible compensate additional attributed IPK based determination ensure all grades preserving entire hierarchical system transferring country.