Title :
Determination of the Avogadro constant from precision density measurements on a silicon sphere
Author :
Kenny, M.J. ; Walsh, C.J. ; Leistner, A.J. ; Fen, K. ; Giardini, W.J. ; Wielunski, L.S. ; Ward, B.R.
Author_Institution :
Nat. Meas. Lab., CSIRO, Lindfield, NSW, Australia
Abstract :
Density measurements with relative uncertainty of 1/spl times/10/sup -7/ have been made on a highly polished 1 kg single crystal silicon sphere. The molar mass, crystal quality and lattice parameter have been measured elsewhere, enabling a determination of the Avogadro constant to be made. The purpose is to obtain a definition of the kilogram in terms of a specific number of /sup 12/C atoms.
Keywords :
atomic mass; constants; density measurement; mass measurement; measurement uncertainty; silicon; 1 kg; Avogadro constant determination; Si; crystal quality; kilogram definition; lattice parameter; molar mass measurement; polished single crystal silicon sphere; precision density measurements; relative uncertainty; sphere roundness; Atmospheric measurements; Atomic measurements; Density measurement; Fabrication; Laboratories; Lattices; Optical interferometry; Optical surface waves; Silicon; Wavelength measurement;
Conference_Titel :
Precision Electromagnetic Measurements Digest, 2000 Conference on
Conference_Location :
Sydney, NSW, Australia
Print_ISBN :
0-7803-5744-2
DOI :
10.1109/CPEM.2000.850937
