@book{JRC41617, editor = {}, address = {Sao Paulo (Brazil)}, year = {2008}, author = {Pereira De Oliveira Junior O and Alonso Munoz A and De Bolle W and Richter S and De Souza Sarkis J and Wellum R}, isbn = {}, abstract = {The establishment of the metrological traceability to a stated reference is a basic requirement for the certification process of reference materials. This important issue was addressed in the very initial step of a programme aimed to the preparation, characterization and certification of uranium isotope reference materials prepared in Brazil. The metrological traceability was accomplished in practice using the power of high precision gas source mass spectrometry (performed at IRMM) to compare the isotope amount ratios in the Brazilian materials to the ratios of special materials certified by the use of synthetic mixtures of highly enriched uranium oxides. The isotope ratios in these mixtures were determined by gravimetry, a primary method of measurement, which enabled a direct link with the International System of Units (SI). The definitions and concepts of the newest edition of the VIM were adopted in this paper. }, title = {Establishing the Metrological Traceability to the SI of the Uranium Isotope Reference Materials Prepared in Brazil}, url = {}, volume = {}, number = {}, journal = {}, pages = {100-106}, issn = {}, publisher = {Instituto de Pesquisas Tecnologicas (IPT)}, doi = {} }