| Copyright note | This is an author-created, un-copyedited version of an article accepted for publication in Metrologia. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version is available online at 10.1088/0026-1394/46/1/001 |
|---|---|
| Title | Mass comparison of the 1kg silicon sphere AVO#3 traceable to the International Prototype K  |
| Author(s) | , , , and |
| Journal | Metrologia |
| Year, Month | 2008, December |
| Volume | 46 |
| Pages | 1-10 |
| DOI | 10.1088/0026-1394/46/1/001 |
| Language | English |
| Keywords | International Prototype K; mass comparison; silicon sphere. |
| Abstract | To determine a new value of the Avogadro constant with a relative combined standard uncertainty of 2×10-8, the mass determination of a 1kg 28Si sphere is crucial and should be determined with the highest level of accuracy. In the next two years the laboratories involved in the International Avogadro Project should be able to determine the mass of a 1kg silicon sphere under vacuum with a combined standard uncertainty within 5µg. To obtain such a target it is essential to gain experience and to promote cooperation in mass measurement on silicon spheres among the laboratories involved. For this purpose an international comparison has been performed to evaluate the weighing procedure and to reveal the diffculties encountered in the mass determination of a silicon sphere. This particular comparison, which is the ?rst international mass comparison under vacuum conditions, has demonstrated that the reference value for the mass of a 1kg silicon sphere can be determined traceable to the International Prototype with a standard uncertainty of 4.0µg. |
| Project title (JRP) | T1.J1.2: NAH: Avogadro and molar Planck constants for the redefinition of the kilogram |
| Funding programme | iMERA-Plus: Call 2007 SI and Fundamental Metrology |