Density of a Single-Crystal Natural Silicon Sphere

Author

Giardini, Walter ; Manson, Peter ; Wouters, Michael ; Warrington, Bruce ; Ward, Brad ; Bignell, Noel ; Walsh, Chris ; Jaatinen, Esa ; Kenny, Michael

Author_Institution

Nat. Meas. Inst., Sydney, NSW

Volume

58

Issue

4

fYear

2009

fDate

4/1/2009 12:00:00 AM

Firstpage

908

Lastpage

914

Abstract

The density of a single-crystal natural silicon sphere identified as ldquoAvo#3rdquo has been redetermined at the National Measurement Institute, Australia (NMIA), as part of an international collaboration to determine the value of the Avogadro constant. A systematic review of the measurement system found that a significant bias was introduced in the measurement of the volume of the sphere, which is calculated from the interferometric measurements of the mean diameter. It was found that the dynamic response of the laser that is used to generate the frequency steps for the phase-shifting interferometry introduced a bias to the returned phase value. We determined the magnitude of the bias and then applied corrections to obtain the final measured value. The density reported here is based on some new and some recalculated measurements taken between April 2000 and May 2006 during the ongoing development of the measurement system.

Keywords

constants; density measurement; diameter measurement; measurement by laser beam; measurement standards; phase shifting interferometry; silicon; volume measurement; Avogadro constant; National Measurement Institute; diameter measurement; interferometric measurement; laser dynamic response; phase-shifting interferometry; single-crystal natural silicon sphere density; sphere volume measurement; Density; interferometry; mass; silicon spheres; volume;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/TIM.2008.2007052

Filename

4694085