Stability of sinkers for establishment of mass standard

摘要

Measurements were performed to determine the mass difference of sinkers used for buoyancy correction to establish national mass standards based on a newly calibrated value of the National Prototype Kilogram (No.6), obtained by the 3rd Periodic Verification at the BIPM. The newly determined value for the mass difference of the sinkers is 260.073 mg and the change in the difference is a 7.3μg increase per year for the last 15 years, equivalent to a 2.4μg increase per year for buoyancy correction.