Diameter Comparison of a Silicon Sphere for the International Avogadro Coordination Project

Author

Kuramoto, Naoki ; Fujii, Kenichi ; Nicolaus, Arnold ; Bartl, Guido ; Gray, Malcolm ; Manson, Peter ; Giardini, Walter

Author_Institution

Nat. Metrol. Inst. of Japan, AIST, Tsukuba, Japan

Volume

60

Issue

7

fYear

2011

fDate

7/1/2011 12:00:00 AM

Firstpage

2615

Lastpage

2620

Abstract

In the International Avogadro Coordination (IAC) Project using the X-ray crystal density method, volume measurements of silicon spheres by optical interferometry play a crucial role for the density measurement of the ²⁸Si-enriched crystal. To confirm the reliability of the volume measurement, specified diameters of a silicon sphere were measured independently by optical interferometers at NMIJ (Japan), PTB (Germany) and NMIA (Australia). The sphere was washed before the measurement with the same procedure. The directions of the diameters were identified with reference marks prepared on the surface of the sphere. All of the results agree with each other within their uncertainties. This strongly confirms the reliability of the diameter and volume measurements in the IAC project.

Keywords

constants; density measurement; light interferometers; light interferometry; volume measurement; X-ray crystal density method; density measurement; diameter comparison; optical interferometers; optical interferometry; silicon sphere; volume measurements; Interferometers; Optical interferometry; Optical variables measurement; Pollution measurement; Silicon; Temperature measurement; Uncertainty; Avogadro constant; X-ray crystal density method; optical interferometry; silicon;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/TIM.2010.2099272

Filename

5740357