title: A Three-Ratio Scheme for the Measurement of Isotopic Ratios of Silicon.
abstract: This paper proposes a scheme of measurement sequences that has been used for the redetermination of the molar mass (atomic weight) of silicon at the Central Bureau for Nuclear Measurements (now Institute for Reference Materials and Measurements). This scheme avoids correlations among the measured ratios caused by normalizing all ion current measurements to that of the largest ion current. It also provides additional information for checking on the consistency of these ratios within a cycle of scans. Measurements of isotope abundance ratios of silicon are used as an illustration.
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
authors.forename: Harry
authors.initials: H
authors.lastname: Ku
authors.affiliation: Institute for Reference Materials and Measurements, Commission of the European Communities, JRC, B-2440 Geel, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Schaefer
authors.affiliation: Institute for Reference Materials and Measurements, Commission of the European Communities, JRC, B-2440 Geel, Belgium.
authors.forename: Staf
authors.initials: S
authors.lastname: Valkiers
authors.affiliation: Institute for Reference Materials and Measurements, Commission of the European Communities, JRC, B-2440 Geel, Belgium.
authors.forename: Paul
authors.initials: P
authors.lastname: De Bièvre
keywords: atomic weight of silicon; isotope ratios; mass spectrometer; measurement scheme; redundancy; symmetry