Title :
Dimensional measurements of a silicon sphere
Author :
Nicolaus, R.A. ; Bonsch, G.
Author_Institution :
Physikalisch Tech. Bundesanstalt, Braunschweig, Germany
Abstract :
For a precision determination of Avogadro´s constant, N/sub A/, the volume of a nearly perfect silicon sphere of 1 kg and about 90 mm diameter, made of a single-crystal, is to be measured with a relative uncertainty of 10/sup -7/. For this, a new interferometric method is used to measure the diameter and its variations in large number of orientations with uncertainties in the sub-nm range.
Keywords :
constants; light interferometry; silicon; volume measurement; Avogadro constant; Si; dimensional measurements; interferometric method; silicon sphere; single crystal; volume measurement; Cameras; Interference; Lenses; Optical interferometry; Optical refraction; Optical surface waves; Optical variables control; Performance evaluation; Silicon; Volume measurement;
Conference_Titel :
Precision Electromagnetic Measurements Digest, 1996 Conference on
Conference_Location :
Braunschweig, Germany
Print_ISBN :
0-7803-3376-4
DOI :
10.1109/CPEM.1996.546754
