Title :
Simulation of convective currents in density measurements of silicon spherical standards [for Avogadro constant redetermination]
Author :
Peuto, A. ; Pettonuso, S. ; Perosino, A. ; Zosi, G.
Author_Institution :
Ist. di Metrol., CNR, Torino, Italy
Abstract :
Within the project on the redetermination of the Avogadro constant through the X-ray-density method, it is necessary to measure the mass of 1 kg silicon spheres with an uncertainty well below 1/spl middot/10/sup -7/. Among the many sources of uncertainty, we investigated the effect of the convective currents caused by temperature gradients inside the weighing chamber.
Keywords :
Constants; Convection; Density measurement; Measurement standards; Measurement uncertainty; Silicon; Weighing; 1 kg; Avogadro constant redetermination; Si; X-ray-density method; balance readings effect; convective currents simulation; density measurements; mass measurement; spherical standards; temperature gradients; uncertainty sources; weighing chamber; Buildings; Current measurement; Density measurement; Measurement standards; Mechanical variables measurement; Prototypes; Shape; Silicon; Steel; Temperature;
Conference_Titel :
Precision Electromagnetic Measurements Digest, 2000 Conference on
Conference_Location :
Sydney, NSW, Australia
Print_ISBN :
0-7803-5744-2
DOI :
10.1109/CPEM.2000.850903
