Ahlers F.,Physikalisch - Technische Bundesanstalt |
Kucera J.,Czech Metrology Institute |
Poirier W.,French National Laboratory of Metrology and Testing |
Jeanneret B.,Federal Institute of Metrology METAS |
And 6 more authors.
CPEM Digest (Conference on Precision Electromagnetic Measurements)
A new joint research project (JRP) integrating metrology institutes and universities from nine countries is aimed at realization of a new generation of standards for quantum resistance metrology. The project exploits graphene's properties to simplify operation of standards without compromising the unprecedented precision delivered by semiconductor quantum Hall devices. Higher operating temperatures (above 4.2 K, and up to 8 K) and together with lower magnetic fields (below 5 T, and potentially down to 2 T) will lead to a significantly improved and cost-saving dissemination of intrinsically referenced resistance standards to all end-users relying on electrical measurements. © 2014 IEEE. Source
Gonzaga F.B.,National Institute of Metrology of Brazil |
Dias J.C.,National Institute of Metrology of Brazil |
Jehnert D.,Zentrum fur Messen und Kalibrieren ANALYTIK GmbH ZMK |
Werner B.,Zentrum fur Messen und Kalibrieren ANALYTIK GmbH ZMK |
And 2 more authors.
This work presents a new differential potentiometric cell for the standardization of pH buffer solutions and its evaluation, by means of a bilateral interlaboratory comparison, in relation to a traditional Baucke cell. The results obtained with the two cells were exactly the same for three of the pH buffer solutions analyzed (1.68, 4.01, and 6.86) and similar to each other for the remaining buffer solution (9.18). The new cell showed an average measurement time of only 21minutes, in comparison with one to three hours for other cells described in the literature (including the Baucke cell). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source
Duewer D.L.,U.S. National Institute of Standards and Technology |
Pratt K.W.,U.S. National Institute of Standards and Technology |
Cherdchu C.,National Institute of Metrology Thailand NIMT |
Tangpaisarnkul N.,National Institute of Metrology Thailand NIMT |
And 5 more authors.
Accreditation and Quality Assurance
The key comparison (KC) studies of the Consultative Committee for Amount of Substance—Metrology in Chemistry help ensure the reliability of chemical and biochemical measurements relevant to international trade and environmental-, health-, and safety-related decision making. The traditional final evaluation of each measurement result reported by a KC participant is a “degree of equivalence” (DEq) that quantitatively specifies how consistent each individual result is relative to a reference value. Recognizing the impossibility of conducting separate KCs for all important analytes in all important sample matrices at all important analyte levels, emphasis is now shifting to documenting broadly applicable critical or “core” measurement competencies elicited through a series of studies. To better accomplish the necessary synthesis of results, data analysis and display tools must be developed for objectively and quantitatively combining individual DEqs. The information detailed in the 11 KCs of primary method pH measurements publically available as of 2013 provides an excellent “best case” prototype for such analysis. We here propose tools that enable documenting the expected primary pH measurement performance of individual participants between pH 1 and pH 11 and from 15 °C to 37 °C. These tools may prove useful for other areas where the uncertainty of measurement is a predictable function of the measured quantity, such as the stable gases. That results for relatively simple measurement processes can be combined using relatively simple analysis and display methods does not ensure that similarly meaningful summaries can be devised for less well understood and controlled systems, but it provides the incentive to attempt to do so. © 2014, The Author(s). Source
Be M.-M.,CEA Saclay Nuclear Research Center |
Isnard H.,CEA Saclay Nuclear Research Center |
Cassette P.,CEA Saclay Nuclear Research Center |
Mougeot X.,CEA Saclay Nuclear Research Center |
And 15 more authors.
New measurements have been undertaken to determine the half-life of 151Sm. A pure 151Sm solution was obtained after chemical separation from a samarium solution resulting from the dissolution of an irradiated samarium sample. The concentration of 151Sm in the solution was measured by mass spectrometry, combined with the isotope dilution technique. The activity of the solution was measured by liquid scintillation counting by six European laboratories as part of an international comparison. These combined results lead to a half-life of T1/2=94.6(6)a. © 2015 Walter de Gruyter Berlin/Boston 2015. Source