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Procedures for high accuracy measurements of ratios of amounts of gas isotopes as used to improve knowledge of the Avogadro constant and checked for quantitative conformity against kinetic gas theory, were used to measure synthetic mixtures of enriched gas isotopes (Xe), prepared by (micro-)gravimetry as commonly used in the preparation of synthetic gas compound mixtures. This enabled a totally independent evaluation of the relative combined standard uncertainty of the procedure to perform direct measurements of ratios of amount of gas isotopes in the redetermination of the Avogadro constant and the gravimetric preparation procedure, both on the same samples.

The results of both procedures, mass spectrometry and gravimetry, agree to 2E-3 expanded uncertainty for amount measurements of the major abundant isotopes. A direct measurement of isotopic gas mixtures has become possible for xenon isotopes and probably other gaseous isotopes. .

Additional information

Authors: AREGBE Y, JRC Geel (BE);VALKIERS S, JRC Geel (BE);DE BIÈVRE P, JRC Geel (BE);MAYER K, JRC Karlsruhe (DE);WESSEL R M, Nederlands Meetinstitut, Delft (NL);ALINK A, Nederlands Meetinstitut, Delft (NL)
Bibliographic Reference: Article: Metrologia
Record Number: 199710691 / Last updated on: 1997-06-10
Original language: en
Available languages: en