Influence of the distribution of measuring points on the mean diameter determination of the Avogadro project's silicon spheres
Influence of the distribution of measuring points on the mean diameter determination of the Avogadro project's silicon spheres
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DOI：
10.1088/0957-0233/20/6/065104
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发表时间：
2009-06-01
影响因子：
2.4
通讯作者：
Nicolaus, Arnold
中科院分区：
文献类型：
--
作者：
Bartl, Guido;Nicolaus, Arnold
国际阿伏伽德罗计划的成员旨在重新测定阿伏伽德罗常数，其相对不确定度小于2x 10（-8），以便有资格重新定义千克。因此，在其他量中，由硅单晶制成的球体的体积必须以0.3nm的直径不确定度非常精确地确定。PTB开发了一种特殊的具有球面参考面的斐索干涉仪，可同时提供绝对干涉测量所需的精度和对球体表面的广泛覆盖。由于设置给出的测量位置的固有不平衡分布，必须在不引入数值误差的情况下执行均衡。在本文中，一个适当的程序，使用点分布在一个球体上的描述和特点方面所涉及的点的数量。
The members of the International Avogadro Project are aiming at the redetermination of Avogadro's constant with a relative uncertainty of less than 2x10(-8) in order to be qualified for the redefinition of the kilogram. Therefore, among other quantities, the volume of a sphere made of a silicon single crystal has to be determined very precisely with a diameter uncertainty of 0.3 nm. A special Fizeau interferometer with spherical reference faces has been developed at PTB providing the required precision in absolute interferometry and a generous coverage of the surface of the sphere at the same time. Due to the intrinsic imbalanced distribution of measurement positions given by the setup, an equalization has to be performed without introducing a numerical error. In this paper an appropriate procedure using point distributions on a sphere is described and characterized with regard to the number of points involved.