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1.
CCT-K7水三相点容器国际关键比对 总被引:1,自引:1,他引:0
在国际互认框架内,国家计量标准的国际等效性是通过国际计量委员会(CIPM)的咨询委员会组织的一系列国际关键比对来确定的。温度咨询委员会(CCT)委托国际计量局(BIPM)作为主导实验室组织了由20个国家实验室参加的CCT-K7水三相点容器国际关键比对。比对结果表明:这些国家基准水三相点值在0.171mK范围内一致。此外,为了减小国家实验室复现水三相点的系统差,需要进一步研究同位素组成对水三相点温度的影响以及同位素修正。 相似文献
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Reymann D. Witt T.J. Vrabcek P. Yi-Hua Tang Hamilton C.A. Katkov A.S. Jeanneret B. Power O. 《IEEE transactions on instrumentation and measurement》2001,50(2):206-209
The Bureau International des Poids et Measures (BIPM) carries out a number of comparisons of dc voltage standards with National Metrology Institutes (NMIs). These take the form of on-site comparisons of Josephson standards or bilateral comparisons using traveling standards based on Zener diodes. This paper describes some of the new procedures used in both types of comparison and presents some results of five recent BIPM key comparisons 相似文献
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M. Stevens R. Benyon S. A. Bell T. Vicente 《International Journal of Thermophysics》2008,29(5):1685-1695
In order to effectively implement the Mutual Recognition Arrangement (MRA) of the International Committee for Weights and
Measures (CIPM), national metrology institutes (NMIs) are required to support their claims of calibration and measurement
capability (CMC) with a quality system compliant with ISO/IEC 17025, and with suitable evidence of participation in key or
supplementary comparisons. The CMC review process, both at regional and inter-regional levels, uses criteria that combine
the provisions mentioned above, together with additional evidence demonstrating scientific and technical competence of the
institutes. For dew-point temperatures, there are key comparisons in progress under the Consultative Committee for Thermometry
(CCT) and under the European regional metrology organisation (EUROMET), together with information available on past regional
supplementary comparisons. However, for relative humidity there are, to date, no such comparisons available to support CMC
entries. This paper presents and discusses the results of a preliminary investigation of the use of relative humidity and
temperature transmitters in order to determine their suitability for the intercomparison of standard humidity generators in
support of CMC claims for the calibration of relative humidity instruments. The results of a recent bilateral comparison between
2 NMIs at the extremes of the range up to 98%rh at 70 °C, and down to 1%rh at −40 °C are reported. Specific precautions and
recommendations on the use of the devices as transfer standards are presented. 相似文献
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The results of key comparisons of the national primary standard of Russia for the unit of electrical voltage, the volt, at
the Mendeleev Institute of Metrology (VNIIM) with the Josephson effect voltage standard at the BIPM are reported. For these
measurements, VNIIM provided a voltage measure based on the Josephson effect with a nominal output voltage of 10 V. Measurements
were made with apparatus from the BIPM voltage standard. The VNIIM voltage measure is planned for use as a transfer standard
for comparison with national standards for the volt. The comparisons indicate a high degree of equivalence of the compared
VNIIM and BIPM primary standards with a relative combined standard uncertainty of 2·10–10 at 10 V. 相似文献
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R. I. Stolyarevskaya 《Measurement Techniques》1999,42(1):86-93
The results are considered of a comparison of the national scales of spectral responsivity of 18 national metrological laboratories
including the All-Union Scientific-Research Institute of Optophysical Measurements (VNIIOFI) between themselves and with the
scale of the International Bureau of Weights and Measures (BIPM) in the spectral wavelength range 250–1000 nm using two different
types of silicon photodetector. The comparisons indicated satisfactory agreement between the results of measurements of spectral
responsivity by the participating laboratories. The difference between the spectral responsivity scale of VNIIOFI and that
of the BIPM did not exceed ±0.5% for the visible wavelength range and the near infrared. The maximum difference of the scales
in the near ultraviolet wavelength range was 3.7%.
Translated from Izmeritel'naya Tekhnika, No. 1, pp. 59–63, January, 1999. 相似文献
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基于国际计量委员会流体流量工作组流量领域关键比对的分类体系, 统计了流量领域校准与测量能力(CMC)总数排名前十经济体的校准与测量能力,对各经济体的流量计量基准、标准装置的测量原理、测量范围、标准相对不确定度等进行对比分析,得到各经济体流量领域的校准与测量能力分布和发展现状。针对我国流量领域的CMC现状,提出未来研究方向,为我国流量领域的校准与测量能力复评审提供支撑。 相似文献
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D. T. Burns P. Lamperti M. O’Brien 《Journal of research of the National Institute of Standards and Technology》1999,104(2):135-140
A direct comparison was made between the air-kerma standards used for the measurement of low-energy x rays at the National Institute of Standards and Technology (NIST) and the Bureau International des Poids et Mesures (BIPM). The comparison was carried out at the BIPM using the BIPM reference beam qualities in the range from 10 kV to 100 kV. The results show the standards to be in agreement to around 0.5 % at reference beam qualities up to 50 kV and at 100 kV. The result at the 80 kV beam quality is less favorable, with agreement at the 1 % level. 相似文献
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D. T. Burns M. O’Brien P. Lamperti M. Boutillon 《Journal of research of the National Institute of Standards and Technology》2003,108(5):383-389
The air-kerma standards used for the measurement of medium-energy x rays were compared at the National Institute of Standards and Technology (NIST) and at the Bureau International des Poids et Mesures (BIPM). The comparison involved a series of measurements at the BIPM and the NIST using the air-kerma standards and two NIST reference-class transfer ionization standards. Reference beam qualities in the range from 60 kV to 300 kV were used. The results show the standards to be in agreement within the combined standard uncertainty of the comparison of 0.35 %. 相似文献
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D. T. Burns M. O’Brien 《Journal of research of the National Institute of Standards and Technology》2006,111(5):385-391
A comparison has been made of the air-kerma standards for medium-energy x-rays of the National Institute of Standards and Technology (NIST) and the Bureau International des Poids et Mesures (BIPM). The comparison involved a series of measurements at the BIPM and the NIST using the air-kerma standards and three NIST reference-class transfer ionization chamber standards. Reference beam qualities in the range from 100 kV to 250 kV were used. The results show the standards to be in reasonable agreement within the combined standard uncertainty of the comparison of 0.37 %, although a significant trend with radiation quality is observed and the possible sources discussed. 相似文献
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Randa J. Achkar J. Buchholz F.-I. Colard T. Rice J. Schubert D. Sinclair M. Williams G.L. 《IEEE transactions on instrumentation and measurement》1999,48(2):174-177
We discuss an international comparison of thermal noise-power measurements (GTRF-92-2), which has recently been completed under the auspices of the Consultative Committee for Electricity and Magnetism (CCEM). The noise temperatures of two solid-state sources with GPC-7 connectors were measured at 2, 4, and 12 GHz at the national laboratories in France, Germany, the United Kingdom, and the United States. Good agreement was found among the results from the different laboratories, with all results agreeing within the expanded uncertainties, which ranged from approximately 0.5% to 2.9%. The comparison was performed in accordance with the guidelines recently adopted by the Bureau International des Poids et Mesures (BIPM) 相似文献
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B. N. Taylor 《Journal of research of the National Institute of Standards and Technology》1989,94(2):95-103
This report provides the background for and summarizes the main results of the 18th meeting of the Consultative Committee on Electricity (CCE) of the International Committee of Weights and Measures (CIPM) held in September 1988. Also included are the most important implications of these results. The principal recommendations originating from the meeting, which were subsequently adopted by the CIPM, establish new international reference standards of voltage and resistance based on the Josephson effect and the quantum Hall effect, respectively. The new standards, which are to come into effect starting January 1, 1990, will result in improved uniformity of electrical measurements worldwide and their consistency with the International System of Units or SI. To implement the CIPM recommendations in the U.S. requires that, on January 1, 1990, the value of the U.S. representation of the volt be increased by about 9.26 parts per million (ppm) and the value of the U.S. representation of the ohm be increased by about 1.69 ppm. The resulting increases in the U.S. representations of the ampere and watt will be about 7.57 ppm and 16.84 ppm, respectively. The CCE also recommended a particular method, affirmed by the CIPM, of reporting calibration results obtained with the new reference standards that is to be used by all national standards laboratories. 相似文献
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《IEEE transactions on instrumentation and measurement》1972,21(4):316-319
Using temperature-regulated transportable standard-cell enclosures, the National Bureau of Standards (NBS), under the auspices of the Bureau International des Poids et Mesures (BIPM), during the period June 1971 through June 1972 has carried out a series of direct comparisons of the units of voltage as-maintained by NBS and BIPM, Sèvres, France; the National Physical Laboratory, United Kingdom; the National Research Council, Canada; the National Standards Laboratory, Australia; and the Physikalisch-Technische Bundesanstalt, Germany. The main purpose of these comparisons was to provide a sound basis for intercomparing values of 2e/h obtained at the various national laboratories via the ac Josephson effect in superconductors. It was found that when converted to a common unit of voltage, most measured values of 2e/h agreed with each other to within the 1 to 2 parts in 107 estimated uncertainty (1 standard deviation) of the volt comparisons. This satisfying result would seem to indicate that serious consideration should be given to adopting a single international value of 2e/h for use in maintaining units of voltage. 相似文献
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《IEEE transactions on instrumentation and measurement》1983,32(1):81-83
The results of international comparisons of methane-stabilized He-Ne lasers at ? = 3.39 ?m and iodine-stabilized He-Ne lasers at 633 nm, made by beat frequency techniques, between Bureau International des Poids et Mesures (BIPM) and eleven national laboratories are presented. Generally, the measured frequency differences were inside ±4 × 10-11; but greater frequency differences were observed with some iodine cells (probably as a result of contamination) or when the output power of one laser was two or three times greater than the power of the other laser. 相似文献
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Dale D. Hoppes 《Journal of research of the National Institute of Standards and Technology》1989,94(6):363-366
This report describes the activities discussed at the 10th meeting of Section II of the Consultative Committee on Standards for the Measurement of Ionizing Radiations (Comité Consultatif pour les Etalons de Mesure des Rayonnements Ionisants, CCEMRI) held in May 1989 at Sèvres (France). Topics included present and future international comparisons of activity measurements, the status and possible extension of the International reference system for activity measurements of gamma-ray emitting nuclides, reports from other working groups, accomplishments at the International Bureau of Weights and Measures (Bureau International des Poids et Mesures, BIPM), and progress at member laboratories. 相似文献