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Euramet RMO supplementary comparison low pressure air flow between 25m3/h and 400 m3/h Metrologia (IF 2.4) Pub Date : 2024-02-28 Thomas Wendel, Dr Ibrahim Busuladžić, Christophe Windenberger, Dr Bodo Mickan, Dr Marc de Huu
Main text The purpose of this Supplementary Comparison (SC) for "Low Pressure Air Flow" measurement is to support the Calibration and Measurement Capabilities (CMC) of the participating National Metrology Institutes and Designated Institutes according to CIPM MRA-G-13. The outcome of this comparison should lead to 'a clear and unequivocal' comparison of measurement results between participants.The
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News from the BIPM laboratories—2023 Metrologia (IF 2.4) Pub Date : 2024-02-22 Michael Stock, Patrizia Tavella, Vincent Gressier, Robert Wielgosz, Martin Milton
In order to fulfil its mission to ensure and promote the global comparability of measurements, the BIPM operates laboratories in the fields of physical metrology, time, ionizing radiation and chemistry. These laboratories act as centres for scientific and technical collaboration between Member States providing capabilities for international measurement comparisons on a shared cost basis. They coordinate
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MSL goniospectrophotometer measurement model Metrologia (IF 2.4) Pub Date : 2024-02-21 E Molloy, A Koo
Measurements of both hemispherical reflectance and the bidirectional reflectance distribution function (BRDF) are of interest to a wide range of industries including computer graphics, remote sensing, lighting design, and cosmetics. The scale of directional reflectance is often realised at national metrology institutes using goniospectrophotometers, and by integrating BRDF measurements made over the
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Comparison of methods to determine the fluence of monoenergetic neutrons in the energy range from 30 keV to 14.8 MeV Metrologia (IF 2.4) Pub Date : 2024-02-21 R Nolte, B Lutz
The primary reference instruments for neutron fluence measurements used at the Physikalisch-Technische Bundesanstalt are based on the primary standard for neutron measurements which is the differential neutron–proton scattering cross section. Such instruments require considerable effort for their operation and analysis. Therefore, routine measurements are carried out using a transfer instrument to
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Development and implementation of an automated four-terminal-pair Josephson impedance bridge Metrologia (IF 2.4) Pub Date : 2024-02-19 Yaowaret Pimsut, Stephan Bauer, Marco Kraus, Ralf Behr, Mattias Kruskopf, Oliver Kieler, Luis Palafox
The four-terminal-pair impedance bridge using pulse-driven Josephson voltage standards at PTB has been fully automated. The same bridge configuration was employed to determine R:R and C:C ratios over the frequency range between 53 Hz to 50 kHz. Only minor changes are needed to cover this large frequency range: amplifiers to increase the sensitivity of the current detections for low frequencies and
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Practical realisation of the kelvin by Johnson noise thermometry Metrologia (IF 2.4) Pub Date : 2024-02-15 Samuel P Benz, Kevin J Coakley, Nathan E Flowers-Jacobs, Horst Rogalla, Weston L Tew, Jifeng Qu, D Rod White, Christof Gaiser, Alessio Pollarolo, Chiharu Urano
Johnson noise thermometry (JNT) is a purely electronic method of thermodynamic thermometry. In primary JNT, the temperature is inferred from a comparison of the Johnson noise voltage of a resistor at the unknown temperature with a pseudo-random noise synthesized by a quantum-based voltage-noise source (QVNS). The advantages of the method are that it relies entirely on electronic measurements, and it
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Multi-kilowatt cw laser power measurement comparison between national standards Metrologia (IF 2.4) Pub Date : 2024-02-14 Kyle Rogers, Paul Williams, Marcel Pastuschek, Holger Lecher, Stefan Kück, Marco Lopez, John Lehman
We present here the first comparison between National Metrology Institutes of high accuracy continuous wave optical power measurements in the kilowatt regime. The National Institute of Standards and Technology (NIST) performed measurements with a power meter relying on photon momentum. The Physikalisch-Technische Bundesanstalt (PTB) performed measurements with a modified off-the-shelf thermal power
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The isotopic composition of the new enriched silicon crystal Si28-31Pr11: maintaining the realization and dissemination of the mole and the kilogram via the XRCD method Metrologia (IF 2.4) Pub Date : 2024-02-09 Axel Pramann, Olaf Rienitz
The molar mass and isotopic composition of a new silicon single crystal material (Si28-31Pr11) highly enriched in 28Si has been determined in the context of the x-ray crystal density method used for the realization and dissemination of the SI base units‒the mole and the kilogram. Isotope ratio measurements have been performed using a high-resolution multicollector-inductively coupled plasma mass spectrometer
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A new interpolation equation in the ITS-90 subrange from the triple point of water to the freezing point of indium Metrologia (IF 2.4) Pub Date : 2024-02-01 Kang Lan, Lide Fang, Ying Wang, Zhiru Kang, Suli Sang
For all the subranges above 0.01 °C, other than the interpolation between the triple point of water (TPW) to the melting point of gallium, temperatures on the international temperature scale of 1990 (ITS-90) are specified without the melting point of gallium. This study suggests a new interpolation equation in the subrange from the TPW to the freezing point of indium which is a polynomial of fractional
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Development and evaluation of emulsified reference materials for magnetic resonance imaging Metrologia (IF 2.4) Pub Date : 2024-01-30 Sunyoung Lee, Seonae Hwangbo, Cheolpyo Hong, Changwoo Lee, Hyo-Min Cho
Hepatic steatosis is characterized by an abnormal accumulation of lipids within hepatocytes. Magnetic resonance imaging (MRI) is a widely used noninvasive method that can accurately and objectively quantify liver fat. To evaluate the accuracy of the quantitatively measured fat fraction, stable and homogenous qualified material is needed as a reference. Surfactant-free micro-emulsions of three fat fractions
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Measurement model of circadian action factor of phosphor-converted white LEDs based on photometric, electrical, and thermal properties Metrologia (IF 2.4) Pub Date : 2024-01-30 Xuehua Shen, Huanting Chen, Min Xu, Xiaoxi Ji, Qun Qin
Light stimulus is confirmed to have critical non-visual biological effects on human beings, and thus evaluation of lighting quality should not be limited to traditional visual performance. The circadian action factor (CAF) has been put forward to quantify such non-visual effects of light sources. This paper focuses on studying the photometric, electrical, and thermal properties of widely used phosphor-converted
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Trap induced broadening in a potential hydrogen lattice clock Metrologia (IF 2.4) Pub Date : 2024-01-30 J P Scott, R M Potvliege, D Carty, M P A Jones
We consider the potential use of optical traps for precision measurements in atomic hydrogen (H). Using an implicit summation method, we calculate the atomic polarisability, the rates of elastic/inelastic scattering and the ionisation rate in the wavelength range (395–1000) nm. We extend previous work to predict three new magic wavelengths for the 1S–2S transition. At the magic wavelengths, the 1S–2S
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Comparisons of standards for liquid flow rates under static load changes Metrologia (IF 2.4) Pub Date : 2024-01-26 Miroslava Benkova, Enrico Frahm, Kevin Romieu, Heiko Warnecke, Oliver Büker, Søren Haack, Başak AKSELLİ, Viliam Mazur, Claudia Berkmann, Gediminas Zygmantas, Corinna Kroner
Main text This report presents the results of an inter-laboratory comparison (ILC) organized in order to determine the degrees of equivalence of standards for liquid static flow rates in the range of 50 kg/h to 36 000 kg/h under ambient pressure and temperature conditions. Water was used as the calibration fluid.The objective of the comparison was to support and prove the Calibration and Measurement
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Update of the BIPM comparison BIPM.RI(II)-K1.Cr-51 of activity measurements of the radionuclide 51Cr to include the 2012 result of the KRISS (Rep. of Korea), the 2022 result of the POLATOM (Poland), and to link the 2022 EURAMET.RI(II)-K2.Cr-51 comparison Metrologia (IF 2.4) Pub Date : 2024-01-26 Carine Michotte, Sammy Courte, Romain Coulon, Manuel Nonis, Steven Judge, Tae Soon Park, Jong-Man Lee, K B Lee, T Ziemek, A Listkowska, E Lech, P Saganowski, J Marganiec-Gałązka, R Broda
Main text Two new participations in the BIPM.RI(II)-K1.Cr-51 comparison have been added to the previous results and this has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. A link has been made to the EURAMET.RI(II)-K2.Cr-51 comparison piloted by the POLATOM in 2022, who sent an ampoule from the EURAMET comparison to the International
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Update of the BIPM comparison BIPM.RI(II)-K1.Ge-68 of activity measurements of the radionuclide 68Ge to include the 2021 result of the NIM (China) Metrologia (IF 2.4) Pub Date : 2024-01-26 Carine Michotte, Romain Coulon, Sammy Courte, Vincent Gressier, Manuel Nonis, Haoran Liu, Juncheng Liang, Meiling Liu, Ming Zhang
Main text Since 2013, 6 laboratories have submitted 7 samples of 68Ge to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ge-68. Recently, the NIM (China) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalencebetween each
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Comparison report of the ITS-90 realization at the freezing point of silver between NIM and CMS Metrologia (IF 2.4) Pub Date : 2024-01-25 Jianping Sun, Shu-Fei Tsai, Ting Li
Main text The APMP key comparison APMP.T-K4.1 was initiated on the request of the Center for Measurement Standards, Taiwan (CMS) to link their standards to the Consultative Committee for Thermometry (CCT) Key Comparison (KC) and facilitate the CMS CMC submission. National Institute of Metrology, China (NIM) provided the linkage to the CCT-K4 at the temperature of the freezing point of silver. In the
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Update of the BIPM comparison BIPM.RI(II)-K1.Zn-65 of activity measurements of the radionuclide 65Zn to include the 2015 result of the LNMRI-IRD (Brazil) and the 2018 result of the LNE-LNHB (France) Metrologia (IF 2.4) Pub Date : 2024-01-25 Carine Michotte, Sammy Courte, Romain Coulon, Manuel Nonis, Guy Ratel, Steven Judge, Carole Fréchou, Christophe Bobin, C J da Silva, R L da Silva, J U Delgado, J A Rangel
Main text Since 1977, 19 laboratories have submitted 22 samples of 65Zn to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Zn-65. The LNMRI-IRD (Brazil) and the LNE-LNHB (France) are the latest participants in the comparison and the key comparison reference value (KCRV) has been updated
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Key comparison BIPM.RI(I)-K5 of the air-kerma standards of the CIEMAT, Spain and the BIPM in 137Cs gamma radiation Metrologia (IF 2.4) Pub Date : 2024-01-25 C Kessler, P Roger, N Cornejo Díaz
Main text A first comparison of the standards for air kerma of the Laboratorio de Metrología de Radiaciones Ionizantes - Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (LMRI-CIEMAT), Spain, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 137Cs radiation beam using the radiation protection facility of the International Atomic Energy Agency (IAEA)
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Update of the BIPM comparison BIPM.RI(II)-K1.Tb-161 of activity measurements of the radionuclide 161Tb to include the 2022 result of the NPL (United Kingdom) Metrologia (IF 2.4) Pub Date : 2024-01-25 Carine Michotte, Sammy Courte, Romain Coulon, Manuel Nonis, S Collins, R Shearman, S Kolmogorova, J Keightley, A Pearce, N Ramirez, E Bendall, H Mohamud, J Mewburn-Crook
Main text Since 2019, 2 laboratories have submitted 2 samples of 161Tb to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Tb-161. Recently, the NPL (United Kingdom) participated in the comparison and the key comparison reference value (KCRV) has been evaluated for the first time. The
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Key comparison BIPM.RI(I)-K7 of the air-kerma standards of the BFKH, Hungary, and the BIPM in mammography x-rays Metrologia (IF 2.4) Pub Date : 2024-01-25 C Kessler, D Burns, V Finta
Main text A key comparison has been made between the air-kerma standards of the BFKH, Hungary, and the BIPM in mammography x-ray beams. The results show the standards to agree at the level of the expanded uncertainty of the comparison of 9.2 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database.To reach the main
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Key comparison BIPM.RI(I)-K5 of the air-kerma standards of the BEV, Austria and the BIPM in 137Cs gamma radiation Metrologia (IF 2.4) Pub Date : 2024-01-25 C Kessler, P Roger, A Steurer, W Tiefenboeck, J Doria
Main text A new comparison of the standards for air kerma of the Bundesamt für Eich- und Vermessungswesen (BEV), Austria, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 137Cs radiation beam using the radiation protection facility of the International Atomic Energy Agency (IAEA) in Seibersdof, Austria in April 2023. The comparison was done using the BEV and the BIPM
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Supplementary comparison of national measurement standards of gauge pressure in the range from 1 MPa to 10 MPa Metrologia (IF 2.4) Pub Date : 2024-01-25 A Zuyev, A Bardonov, M Leontyev, K Dapkeviciene
Main text This report gives the results of the supplementary comparison COOMET.M.P-S1 for measurements of the gauge pressure within the range from 1 MPa to 10 MPa. This comparison was piloted by NSC "Institute of Metrology" (Kharkiv, Ukraine). The principle of comparison is to determine the transfer standard effective area of the piston according to the method of cross-float equilibrium of transfer
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Key comparison BIPM.RI(I)-K8 of high dose-rate 192Ir brachytherapy standards for reference air kerma rate of the PTB and the BIPM Metrologia (IF 2.4) Pub Date : 2024-01-24 C Kessler, R Behrens, A Kasper, F Grote
Main text An indirect comparison of the standards for reference air kerma rate for 192Ir high dose rate (HDR) brachytherapy sources of the Physikalisch-Technische Bundesanstalt (PTB), Germany, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the PTB in May 2023. The comparison result, based on the calibration coefficients for a transfer standard and expressed as a ratio
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Final report for SIM.QM-S12: supplementary comparison for trace elements in natural water Metrologia (IF 2.4) Pub Date : 2024-01-24 Patricia Grinberg, Kenny Nadeau, Lu Yang, Zoltan Mester, Wai-hong Fung, Chun-wai Tse, Jeffrey Merrick, Ian White, Isaac Schipp, Osvaldo Acosta, Mabel Puelles, Jose Luis Gonzales Quino, Rodrigo Caciano de Sena, Marcelo Dominguez de Almeida, Emily Silva Dutra, Chao Jingbo, Dong Lijie, Elias Kakoulides, G Karanikolopoulos, E Stathoudaki, Sushree Swarupa Tripathy, Dibya Dolridge Toppo, Jyoti Pokhariyal
Main text The SIM Supplementary Comparison SIM.QM-S12 for Trace Elements in Natural Water was undertaken to assess and demonstrate the analytical capabilities of national metrology institutes (NMIs) and designated institutes (DIs) of SIM members (or other regions) for the accurate determination of trace elements in natural water at µg/kg levels.Evidence of successful participation in formal, relevant
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The CCL-K11 ongoing key comparison. Final report for 2022 Metrologia (IF 2.4) Pub Date : 2024-01-24 M Matus, J-P Wallerand, R Fira, G Zechner
Main text Two lasers from two national metrological institutes (NMIs) were compared in the year 2022 as part of the CCL-K11 ongoing key comparison, initiated by the 13th meeting of the Comité Consultative des Longuers (CCL) in 2007. The absolute frequency of R(127) 11-5 (≈633 nm) transitions of molecular iodine was measured for these lasers following the technical protocol for CCL-K11. The results
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Evaluation of the relativistic redshift in frequency standards at KRISS Metrologia (IF 2.4) Pub Date : 2024-01-22 Jisun Lee, Jay Hyoun Kwon, Chang Yong Park, Huidong Kim, In-Mook Choi, Jin Wan Chung, Won-Kyu Lee
Relativistic redshift correction should be accurately considered in frequency comparisons between frequency standards. In this study, we evaluated the relativistic redshift at Korea Research Institute of Standards and Science (KRISS) using three different methods, depending on whether the approach was traditional or modern or whether the geopotential model was global or local. The results of the three
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Roadmap towards the redefinition of the second Metrologia (IF 2.4) Pub Date : 2024-01-22 N Dimarcq, M Gertsvolf, G Mileti, S Bize, C W Oates, E Peik, D Calonico, T Ido, P Tavella, F Meynadier, G Petit, G Panfilo, J Bartholomew, P Defraigne, E A Donley, P O Hedekvist, I Sesia, M Wouters, P Dubé, F Fang, F Levi, J Lodewyck, H S Margolis, D Newell, S Slyusarev, S Weyers, J-P Uzan, M Yasuda, D-H Yu, C Rieck, H Schnatz, Y Hanado, M Fujieda, P-E Pottie, J Hanssen, A Malimon, N Ashby
This paper outlines the roadmap towards the redefinition of the second, which was recently updated by the CCTF Task Force created by the CCTF in 2020. The main achievements of optical frequency standards (OFS) call for reflection on the redefinition of the second, but open new challenges related to the performance of the OFS, their contribution to time scales and UTC, the possibility of their comparison
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APMP.QM-S19: Toxic elements in seafood Metrologia (IF 2.4) Pub Date : 2024-01-19 Kelvin Chun-wai Tse, Wai-hong Fung, Mala Khan, Soraya Sandoval Riquelme, Javier Vera, Li Xiao, Lu Hai, Ronald Cristancho, Adriana Rodriguez, Diego A Garzon Z , Carlos Andres España, Elias Kakoulides, G Karanikolopoulos, E Stathoudaki, V Schoina, Christine Elishian, Isna Komalasari, Luigi Bergamaschi, Giancarlo D'Agostino, Marco di Luzio, Shin-ichi Miyashita, Maria-del-Rocio Arvizu-Torres, Emilia Vasileva-Veleva
Main text Seafood is one of the major food resources for human consumption in the world. The CODEX Alimentarius Commission and many jurisdictions have set maximum levels of metallic contaminants in seafood. The use of reliable methods for measurement of metallic contaminants is important in safeguarding the quality of these products and public health.The Supplementary Comparison APMP.QM-S19: Toxic
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Supplementary comparison SIM.M.FF-S9.2016 for water flow measurement Metrologia (IF 2.4) Pub Date : 2024-01-19 E Frahm, R Arias, M Maldonado, J Vargas, J J Mendoza, A Arredondo, M A Silvosa
Main text The objective of the Supplementary Comparison (SC) SIM.M.FF-S9 for water flow measurement was to support and prove the Calibration and Measurement Capabilities (CMC) of the participating NMIs of Chile (CISA), Peru (INACAL), Bolivia (IBMETRO) and Argentina (INTI). As pilot laboratories, the national metrology institutes of Germany (PTB) and CENAM (Mexico) supported the comparison with reference
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CCEM key comparison CCEM.RF-K26. Attenuation at 18 GHz, 26.5 GHz and 40 GHz using a step attenuator. Final report of the pilot laboratory Metrologia (IF 2.4) Pub Date : 2024-01-19 A Widarta
Main text This report summarizes the results of the Key Comparison CCEM.RF-K26 Attenuation at 18 GHz, 26.5 GHz and 40 GHz using a step attenuator which has been performed from January 2015 to February 2018. Fourteen National Metrology Institutes (NMIs) participated in this key comparison, including the National Metrology Institute of Japan (NMIJ/AIST, Japan) which served as pilot laboratory, the National
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International comparison of measurements of neutron source emission rate (2016-2021) - CCRI(III)-K9.Cf.2016 Metrologia (IF 2.4) Pub Date : 2024-01-19 N J Roberts, N A Horwood, Z Vykydal, H Park, J Kim, W W Pereira, E S da Fonseca, C Thiam, Zhang Hui, M S Dewey, H P Mumm, H Harano, T Matsumoto, A Masuda, S Manabe, J P Archambault, N N Moiseev, A V Didyk
Main text Section III (neutron measurements) of the Comité Consultatif des Rayonnements Ionisants, CCRI, conducted a comparison of primary measurements of the neutron emission rate of a 252Cf radionuclide source. A single 252Cf source was circulated to all participants between 2016 and 2020. Ten laboratories participated -CMI (Czech Republic), KRISS (Republic of Korea), IRD/LNMRI (Brazil), LNE-LNHB
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Length measurement based on multi-wavelength interferometry using numerous stabilized frequency modes of an optical comb Metrologia (IF 2.4) Pub Date : 2024-01-18 Jungjae Park, Yoon-Soo Jang, Jonghan Jin
The electro-optic comb (EO comb) with a relatively wide mode spacing of 25 GHz can be resolved into individual frequency modes with a commercially available high-resolution spectrometer. The EO comb has numerous discrete frequency modes, which can serve as a light source for a monochromatic laser interferometer to realize the meter. In this study, a method for measuring the absolute distances based
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A strontium lattice clock with both stability and uncertainty below 5×10−18 Metrologia (IF 2.4) Pub Date : 2024-01-12 Jie Li, Xing-Yang Cui, Zhi-Peng Jia, De-Quan Kong, Hai-Wei Yu, Xian-Qing Zhu, Xiao-Yong Liu, De-Zhong Wang, Xiang Zhang, Xin-Yun Huang, Ming-Yi Zhu, Yu-Meng Yang, Yi Hu, Xiang-Pei Liu, Xiao-Min Zhai, Peng Liu, Xiao Jiang, Ping Xu, Han-Ning Dai, Yu-Ao Chen, Jian-Wei Pan
We report the realization of the closed-loop operation of an optical lattice clock based on 87Sr atoms. A cavity-stabilized 698 nm laser is used to probe the 1S0→3P0 clock transition of strontium atoms trapped in optical lattices. Therein, we obtain a Fourier-limited Rabi spectrum with 0.6 Hz linewidth. The two transitions from mF=±9/2 ground states are alternatively interrogated to realize the closed-loop
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A Bayesian statistical method for large-scale MEMS-based sensors calibration: a case study on 100 digital accelerometers Metrologia (IF 2.4) Pub Date : 2023-12-28 Andrea Prato, Francesca Pennecchi, Gianfranco Genta, Alessandro Schiavi
Low-cost sensors and in particular micro-electro-mechanical systems (MEMS) devices are widely used in many applications, including consumer electronics, healthcare, automotive, and industrial automation. Their large-scale production (typically in the order of millions per week in a single factory) would require the calibration of a huge number of devices that would be costly and time-consuming. A solution
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Higher-order Allan variance for atomic clocks of arbitrary order: mathematical foundation Metrologia (IF 2.4) Pub Date : 2023-12-20 Takayuki Ishizaki, Taichi Ichimura, Takahiro Kawaguchi, Yuichiro Yano, Yuko Hanado
In this paper, we perform a time-domain analysis of the higher-order Allan variance for atomic clock models of arbitrary order. Adopting a standard atomic clock model where the time series of the clock reading deviation is expressed as a Wiener or integrated Wiener process, we define the higher-order Allan variance as the mean squared higher-order difference of the clock reading deviation. The main
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Characterization of laser-pumped Cs-4He atomic magnetometer Metrologia (IF 2.4) Pub Date : 2023-12-20 Hao Liu, Jia Kong, Jiqing Fu, Shurui Yang, Xiao-Ming Lu, Xiaoguang Wang
In principle, laser-pumped Cs–4He magnetometers can take advantage of the high sensitivity of optically pumped magnetometers and the high accuracy of proton magnetometers. However, insufficient experimental studies have been conducted on the optimization conditions and physics of this type of magnetometer. In this study, we investigate the experimental performance of a laser-pumped Cs–4He magnetometer
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On the distinction between SI base units and SI derived units Metrologia (IF 2.4) Pub Date : 2023-12-19 Richard J C Brown
This letter discusses the criteria that should be considered when deciding whether or not the distinction between base units and derived units in the International System of Units (SI) is useful, a debate that has been reignited following the 2019 revision of the SI. It is proposed that the correct question to ask is whether the concept of independent quantities, and the dimensional analysis it allows
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Multi-taper-based automatic correction of non-anechoic antenna measurements Metrologia (IF 2.4) Pub Date : 2023-12-07 Mariusz Dzwonkowski, Vorya Waladi, Adrian Bekasiewicz
Prototype measurements belong to the key steps in the development of antenna structures. Although accurate validation of their far-field performance can be realized in dedicated facilities, such as anechoic chambers, the high cost of their construction and maintenance might not be justified if the main goal of measurements is to support teaching or low-budget research. Instead, they can be performed
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Spectral analysis of deviations from key comparison reference values Metrologia (IF 2.4) Pub Date : 2023-11-27 Kinza Maham, Vili Kosonen, Juha Peltoniemi, Petri Kärhä, Erkki Ikonen
When studying the results of the key comparisons of spectral quantities, it appears that in many cases participants’ results systematically deviate from the key comparison reference values over a limited spectral range. We carried out spectral analysis of such deviations in seven key comparisons of optical radiometry. The results reveal an approximate outcome that, on the average, each harmonic amplitude
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Ambient humidity, the overlooked influencer of radioactivity measurements Metrologia (IF 2.4) Pub Date : 2023-11-27 S Pommé, H Stroh, T Altzitzoglou, J Paepen, R Van Ammel, M Marouli, L Verheyen, M Unterweger, R Fitzgerald, D E Bergeron, L Pibida, O Nähle, K Kossert, N Ramirez, E Bendall, A Fenwick, K Ferreira, J Keightley, M Baker, S Collins, C Michotte, S Courte, R Coulon, T W Jackson, W M Van Wyngaardt, A Fazio, P De Felice, B Vodenik, M Korun, F Juget, C Bailat, Y Nedjadi, F Bochud, T Buchillier, T Roy, R Galea
When verifying the validity of the exponential-decay law through 137 precise decay rate measurement series at various nuclear laboratories, minor violations have been observed in the shape of annual cycles in the residuals with different amplitudes and phase shifts. The timing and amplitude of these deviations have been compared with local weather data and it appears that ambient humidity is highly
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COOMET regional comparison of the national standards of air kerma for x-radiation qualities used for radiation protection and diagnostic radiology (COOMET.RI(I)-S3) Metrologia (IF 2.4) Pub Date : 2023-11-23 Siarhei Saroka, Gonzalo Walwyn Salas, Efimia Luchian, Ludwig Büermann, Alexandr Oborin, Simon Sukhishvili, Paula Toroi, Elmar Shahverdiyev, Andrey Orobinski, Nasir Mamyrbek
Main text The results of the COOMET supplementary comparison of the national measurement standards of air kerma for x-radiation qualities used for radiation protection and diagnostic radiology are presented. Nine National Metrology Institutes from the COOMET organization and the International Atomic Energy Agency participated in this COOMET project no.641. The BelGIM acted as a pilot laboratory. The
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Update of the BIPM comparison BIPM.RI(II)-K1.Na-22 of activity measurements of the radionuclide 22Na to include the 2022 result of the NMISA (South Africa) Metrologia (IF 2.4) Pub Date : 2023-11-23 Romain Coulon, Carine Michotte, Sammy Courte, Manuel Nonis, Milton W Van Rooy, Joline Lubbe, Martin J van Staden
Main text Since 1976, 13 laboratories have submitted 30 samples of 22Na to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Na-22. Recently, the NMISA (South Africa) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence
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Final report for CCQM-P212: coherence of carbon isotope delta reference materials Metrologia (IF 2.4) Pub Date : 2023-11-23 Michelle M G Chartrand, Fong-Ha Liu, Jeffrey P Merrick, Maíra Fasciotti, Bruno Carius Garrido, Eliane Cristina Pires do Rego, Thays Vieira da Costa Monteiro, Wagner Wollinger, Heiko Moossen, Heike Geilmann, Ian Chubchenko, Anna Kolobova, Nives Ogrinc, Doris Potočnik, Philip J H Dunn, Heidi Goenaga-Infante, Sarah Hill, Dmitriy Malinovsky, Zoltán Mester, Juris Meija
Main text This pilot study evaluates the coherence of carbon isotope delta reference materials (RMs) used by laboratories worldwide. The goal was to assess how well laboratories can realize the VPDB scale using these RMs. In total, carbon isotope delta values of 36 RMs were measured by seven laboratories as well as the vanillin sample previously evaluated in CCQM-K167/P211. A hierarchical Bayesian
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International comparison EURAMET.QM-K3.2019 - automotive exhaust gases Metrologia (IF 2.4) Pub Date : 2023-11-23 Ruben P Ziel, E Zalewska, Adriaan M H van der Veen, Heinrich Kipphardt, Dirk Tuma, Andres Rojo Esteban, Teresa E Fernández Vicente, Tatiana Macé, Christophe Sutour, Fabrice Marioni, Judit Fükő, László Szűcs, Tamás Büki, Zsófia Nagyné Szilágyi, Dariusz Cieciora, Grzegorz Ochman, Przemysław Romanowski, Anna Lis, Magdalena Garnuszek, Miroslava Valkova, Andreas Ackermann, Celine Pascale, Bernhard Niederhauser
Main text EURAMET.QM-K3.2019 was a repeat of the key comparison EURAMET.QM-K3 on the composition of automotive exhaust gases. New in EURAMET.QM-K3.2019 was the addition of the amount fraction oxygen to the programme. The key comparison reference values were obtained independently, using static gravimetry and appropriate corrections from purity analysis and are linked to those of CCQM-K3.2019. The key
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Final report of CCQM-P225a and b, international comparison on carbon dioxide in air and nitrogen at ambient levels (350 μmol/mol to 800 μmol/mol) Metrologia (IF 2.4) Pub Date : 2023-11-23 J Viallon, T Choteau, P Moussay, R I Wielgosz, A M H van der Veen, Z Bi, A Crotwell, B Hall, E Mussel Webber, R Hill−Pearce, P Brewer, D Worton, T Macé, C Sutour
Main text The pilot studies CCQM-P225a and b aimed at validating the performance of the pVT−CO2 manometric reference facility maintained at the BIPM as a reference for the planned ongoing comparisons BIPM.QM-K2a and b for CO2 in air and nitrogen standards, respectively, over the range 350 μmol mol−1 to 800 μmol mol−1. The planned launch date of the BIPM.QM-K2a and b comparisons is 2024 and will enable
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Final report on APMP.EM-K2 key comparison of resistance standards at 10 MΩ and 1 GΩ Metrologia (IF 2.4) Pub Date : 2023-11-23 Kwang Min Yu, Wan Seop Kim
Main text In order to link the National Metrology Institutes (NMI) organized in Asia Pacific Metrology Programme (APMP) to the key comparison CCEM-K2, APMP.EM-K2 key comparison was piloted by the Korea Research Institute of Standards and Science (KRISS), beginning in July 2010 and completed July 2014 with the participation of 13 National Metrology Institutes (NMIs). The results of this key comparison
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Supplementary comparison SIM.QM-S06 - automotive exhaust gases (CO, CO2, C3H8) Metrologia (IF 2.4) Pub Date : 2023-11-23 Cristiane R A C Iglesias, Andreia L Fioravante, Claudia C Ribeiro, Viviane F Mello, Rocio C T Zambrano, Steve A Acco García, Florencia Almirón
Main text Supplementary comparison of carbon monoxide, carbon dioxide and propane in nitrogen (model 1).To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the
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A high accuracy reference facility for ongoing comparisons of CO2 in air standards Metrologia (IF 2.4) Pub Date : 2023-11-20 J Viallon, C Meyer, P Moussay, J Schmidt, S Maxwell, F Arrhen, R I Wielgosz
The design, performance characteristics and validation of a next generation reference facility for carbon dioxide (CO2) in air standards based on manometry is presented. Novel attributes of the facility include automated operation, avoidance of significant pressure corrections for measurements on extracted CO2, fully characterized trapping efficiencies, and reduced measurement uncertainty. Improvements
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Evaluation of long-term robustness of the International System of Reference (SIR) used in radionuclide metrology based on the meta-analysis of its machine-readable database Metrologia (IF 2.4) Pub Date : 2023-11-17 Romain Coulon, Carine Michotte, Vincent Gressier
In support of the CIPM MRA, the reference system in radionuclide metrology (SIR) is a unique experimental facility that has been able to provide continuous key comparison results for 72 radionuclides for 46 years. These measurement data are now available in a machine-readable format, which allows statistical analysis of these measurement results to be performed efficiently. Such a meta-analysis was
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Small corrections to 1989 NIST constant-volume gas thermometry data Metrologia (IF 2.4) Pub Date : 2023-11-17 Allan H Harvey
Constant-volume gas thermometry data published in 1989 for the difference between the thermodynamic temperature and the International Practical Temperature Scale of 1968 are corrected in two ways. A refined estimate of the thermal expansivity of the material of the gas bulb, published in 1990, increases the thermodynamic temperature by amounts on the order of 1 mK–3 mK. Better knowledge of the nonideality
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Key comparisons of air kerma and absorbed dose to water standards in 60Co radiation beam (EURAMET.RI(I)-K1.3 and EURAMET.RI(I)-K4.3) Metrologia (IF 2.4) Pub Date : 2023-11-16 R Nylund, L A de Prez, P O Hetland, C E Andersen, P Aviles, C G Mulas, Z Msimang, L Czap, L Persson
Main text A key comparison of the standards for air kerma and absorbed dose to water of seven participating laboratories was carried out in the 60Co radiation beam, therapy level, during October 2021 to November 2022. Six of the participating laboratories are secondary standards laboratories (SSM, DSA, STUK, DTU, CIEMAT, and IAEA) and VSL is a primary standards laboratory and acted as a linking laboratory
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Supplementary comparison SIM.QM-S9 - biogas Metrologia (IF 2.4) Pub Date : 2023-11-16 Cristiane R A C Iglesias, Andreia L Fioravante, Claudia C Ribeiro, Viviane F Mello, Jorge Koelliker Delgado, Diana Gabriela Ramírez Flores, Francisco Rangel Murillo, Carlos Ramírez Nambo, Maria Mabel Puelles, Andrea Luján Chamorro, Yamil Acho Sarzuri
Main text Supplementary comparison of amount fractions methane, nitrogen, carbon dioxide, hydrogen and oxygen (constituting a mixture of biogas).To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the
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Final report of CCQM-P204, comparison on CO2 isotope ratios in pure CO2 Metrologia (IF 2.4) Pub Date : 2023-11-14 J Viallon, T Choteau, E Flores, F Idrees, P Moussay, R I Wielgosz, Z Loh, C Allison, L Huang, A Chivelscu, F Camin, B Krajnc, N Ogrinc, A de Lima Fioravante, M Fasciotti, T V C Monteiro, B C Garrido, E C P Rego, W Wollinger, C R Augusto, S Michel, J S Lee, J K Lim, M Daëron, S Kassi, H Moossen, L Hai, Z Zhou, A Srivastava, T Shimosaka, E Mussel Webber, R Hill−Pearce, P Brewer, M Chartrand, O Rienitz
Main text The pilot study CCQM-P204 was aimed at evaluating the level of compatibility of laboratories' measurement capabilities to value assign isotope ratios in samples of pure CO2 gas, expressed as isotope delta values relative to the relevant international scale: δ13CVPDB and δ18OVPDB-CO2.Pure CO2 gas samples were prepared by the BIPM in batches of 10 samples of the same gas and circulated to participants
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First evaluation of the primary frequency standard NTSC-CsF2 Metrologia (IF 2.4) Pub Date : 2023-11-13 Xin-Liang Wang, Jun Ruan, Dan-Dan Liu, Yong Guan, Jun-Ru Shi, Fan Yang, Yang Bai, Hui Zhang, Si-Chen Fan, Wen-Jun Wu, Shu-Hong Zhao, Shou-Gang Zhang
Caesium fountain primary frequency standards have been used to realize the definition of the second in the International System of units for more than two decades. This paper reports the structure and uncertainty evaluation of the NTSC-CsF2, developed by National Time Service Center (NTSC), Chinese Academy of Sciences. The short-term stability at high atomic density is 2.1 × 10−13 at 1 s of averaging
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Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with ISCIII, May 2023 Metrologia (IF 2.4) Pub Date : 2023-11-10 Joële Viallon, Faraz Idrees, Philippe Moussay, Robert Wielgosz, Beatriz Nunez-Corcuera, Saúl Garcia Dos Santos-Alves
Main text As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of the Instituto de Salud Carlos III (ISCIII) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol mol−1
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Statistics for quantifying aging in time transfer system delays Metrologia (IF 2.4) Pub Date : 2023-11-10 T E Parker, R C Brown, J A Sherman
Residual time delays in time transfer systems such as two-way satellite time and frequency transfer (TWSTFT), or GPS carrier phase (GPSCP) change over time. A double difference such as TWSTFT—GPSCP provides information on the changes in the relative time delays of the two systems. These changes are referred to as aging or time dispersion. A first difference statistic, RMS time interval error, TIERMS
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Monitoring of the offset between UTC and its prediction broadcast by the GNSS Metrologia (IF 2.4) Pub Date : 2023-11-06 P Defraigne, E Pinat, G Petit, F Meynadier
We present a new approach to report, in the section of International Bureau of Weights and Measures Circular T, daily values of the offset between Coordinated Universal Time (UTC) and the predictions of UTC broadcast by the Global Navigation Satellite Systems (GNSS), this quantity we name bUTCGNSS. In this approach, the determination of UTC-bUTCGNSS is based on data collected by several multi-GNSS
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AFRIMETS.L-S6 supplementary comparison: comparison on hand instruments (50 mm micrometer setting piece, 0-25 mm and 50-75 mm external micrometers) Metrologia (IF 2.4) Pub Date : 2023-11-06 Burnhard Panda Gandah, Zanele Nzimande
Main text Nine AFRIMETS National Metrology Institutes participated in an interlaboratory comparison on hand instruments sponsored by PTB Germany during the period 2019 to 2022. SIRDC NMI piloted the comparison. Travelling artefacts included 0-25 mm and 50-75 mm external micrometers. External micrometer errors of indicated size were determined by taking measurements at 2.5 mm, 5.1 mm, 7.7 mm, 10.3 mm
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Update of the BIPM comparison BIPM.RI(II)-K1.Lu-177 of activity measurements of the radionuclide 177Lu to include the 2013 result of the IFIN-HH (Romania), the 2014 result of the LNE-LNHB (France) and the 2022 result of the IRA (Switzerland) Metrologia (IF 2.4) Pub Date : 2023-11-01 Romain Coulon, Carine Michotte, Sammy Courte, Manuel Nonis, Guy Ratel, Steven Judge, Maria Sahagia, Aurelian Luca, Andrei Antohe, Mihail-Razvan Ioan, Frederic Juget, Youcef Nedjadi, Teresa Duran, Christophe Bobin, Carole Fréchou
Main text Since 2000, 7 laboratories have submitted 7 samples of 177Lu to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Lu-177. Recently, the IFIN-HH (Romania), the LNE-LNHB (France) and the IRA (Switzerland) participated in the comparison. The degrees of equivalence between each equivalent
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Final Report on COOMET Supplementary Comparison COOMET.PR-S5 (COOMET 429/CU/08) Metrologia (IF 2.4) Pub Date : 2023-11-01 Sandra Pedro Valdés, Juliana F S Gomes, Olga Tarasova, Zuzana Tunegova, Marian Krempasky, Mykola Huriev, Nataliya Parkhomenko
Main text This report gives the results of the COOMET Supplementary Comparison COOMET.PR-S5 of Regular Spectral Transmittance 250 nm to 635 nm (COOMET Project 429/CU/08).The NIM participating in the comparison are: National Metrology Research Institute of Cuba (INIMET), Brazilian National Institute of Metrology, Standardization and Industrial Quality (INMETRO), State Institute of Metrology of Belarus