[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Development of a Specialized Hydrostatic Comparator for the Accurate Density Determination of Natural Silicon Spheres: A Novel Method for a Primary Realization of the Unit Kilogram

摘要： A novel method to primary realize the soon-to-be redefined unit of mass, kilogram, is presented. The new approach will accurately relate the Planck constant to spheres manufactured from natural silicon. Therefore, the precisely known isotopical composition of a 28Si sphere will be transferred to a sphere made of natural silicon with a relative uncertainty of 3 x 10-8. To achieve this objective, the concept of a newly developed hydrostatic comparator, which combines the Archimedes principle with a magnetic suspension coupling, is discussed. This combination allows to improve the major uncertainty contribution of this type of instrument — the temperature stability.