XXIV IMEKO World Congress 2024 "Think Metrology", Hamburg, 26-29, August, 2024, Germany
Freie Schlagworte
silicon spheres ; kilogram ; density ; hydrostatic weighing ; density comparison
Zusammenfassung
Since the establishment of the revised SI the unit of mass “kilogram” can be realized by two independent primary methods (the "Kibble balance method" or the "X-ray crystal density method”, XRCD) related to the Planck’s constant. In addition, the XRCD method is also a primary realization of the density unit using spheres of highly enriched 28Si. In contrast to the realization method based on very expensive 28Si spheres, a more cost-effective method has been developed to disseminate the density unit using spheres of monocrystalline natural silicon. A well characterized 28Si sphere will be used as reference for the calibration of the density of spheres made of natural silicon. So far, the use of a pressure-stabilized hydrostatic weighing apparatus seems to offer the best possibility to perform the necessary density comparison measurement with smallest uncertainties. This apparatus is developed to ensure high pressure and temperature stability by shielding the atmosphere inside the comparator from the environment. The concept of a pressure-stabilized hydrostatic weighing system is presented here.
Grundlagen der Metrologie
; Metrologie für die Wirtschaft
Zitierung
Eppers, D. & Knopf, D. (2025). Dissemination of the density unit using 1 kg spheres made of natural silicon by pressure-stabilised hydrostatic weighing. Measurement: Sensors, 38(Suppl.), e1–e4. https://doi.org/10.1016/j.measen.2024.101349
