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  • Report on the CCM key comparison of kilogram realizations CCM.M-K8.2019
    Metrologia (IF 2.28) Pub Date : 2020-10-30
    M Stock, P Conceição, H Fang, F Bielsa, A Kiss, L Nielsen, D Kim, M Kim, K -C Lee, S Lee, M Seo, B -C Woo, Z Li, J Wang, Y Bai, J Xu, D Wu, Y Lu, Z Zhang, Q He, D Haddad, S Schlamminger, D Newell, E Mulhern, P Abbott, Z Kubarych, N Kuramoto, S Mizushima, L Zhang, K Fujita, S Davidson, R G Green, J O Liard, N F Murnaghan, C A Sanchez, B M Wood, H Bettin, M Borys, M Mecke, A Nicolaus, A Peter, M Müller

    This report describes the first CCM key comparison of realizations of the kilogram definition based on the fixed numerical value of the Planck constant, which came into force on 20 May 2019. The objectives were to determine the level of agreement between realizations of the kilogram using Kibble and joule balances and the X-ray crystal density (XRCD) method and to provide input for the calculation

    更新日期:2020-10-30
  • Bayesian inference for heterogeneity in meta-analysis
    Metrologia (IF 2.28) Pub Date : 2020-10-30
    Olha Bodnar, Rebecca Nalule Muhumuza and Antonio Possolo

    A generalized marginal random effects model is described that enables exact Bayesian inference using either the Jeffreys or Berger-Bernardo non-informative prior distributions without the need for Markov Chain Monte Carlo sampling, requiring only numerical integrations. This contribution focuses on inference for the heterogeneity parameter, often called “dark uncertainty” and denoted τ in this contribution

    更新日期:2020-10-30
  • Precision measurement of single-electron current with quantized Hall array resistance and Josephson voltage
    Metrologia (IF 2.28) Pub Date : 2020-10-30
    Myung-Ho Bae, Dong-Hun Chae, Mun-Seog Kim, Bum-Kyu Kim, Suk-In Park, Jindong Song, Takehiko Oe, Nobu-Hisa Kaneko, Nam Kim and Wan-Seop Kim

    A single electron pump was incorporated with a quantum Hall resistance and a Josephson voltage for the current evaluation in the framework of Ohm’s law. The pump current of about 60 pA level was amplified by a stable amplifier with a gain of 10 3 to induce a Hall voltage of about 60 mV level across a 1 MΩ Hall resistance array, which was compared with the Josephson voltage. The gain of the current

    更新日期:2020-10-30
  • Absolute frequency measurement of an Yb optical clock at the 10 −16 level using International Atomic Time
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    Limeng Luo, Hao Qiao, Di Ai, Min Zhou, Shuang Zhang, Sheng Zhang, Changyue Sun, Qichao Qi, Chengquan Peng, Taoyun Jin, Wei Fang, Zhiqiang Yang, Tianchu Li, Kun Liang and Xinye Xu

    We report on the absolute frequency measurement of the 6 s 2 1 S 0 –6 s 6 p 3 P 0 transition in 171 Yb with a fractional uncertainty of 7.3 × 10 –16 . A global positioning system carrier phase frequency transfer was established between National Institute of Metrology of China and East China Normal University, which linked the optical frequency of the ECNU Yb1 clock to the second in the International

    更新日期:2020-10-30
  • Analysis on the time transfer performance of BDS-3 signals
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    Wei Guang, Jihai Zhang, Haibo Yuan, Wenjun Wu and Shaowu Dong

    The BeiDou global navigation satellite system (BDS-3) was formally commissioned to provide positioning, velocity, and timing services to global users on 31 July 2020. We analyzed its pseudorange measurement noise, the precision of conventional common view (CV) and all-in-view (AV) time comparison, and the instability of the precise point positioning (PPP) time transfer to assess the time transfer performance

    更新日期:2020-10-30
  • A first step towards the introduction of redundant time links for the generation of UTC: the calculation of the uncertainties of [UTC-UTC( k )]
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    G Panfilo, G Petit and A Harmegnies

    In this paper a new algorithm for the introduction of redundant time links in UTC calculation is presented. This algorithm is first applied for the evaluation of the uncertainty of [UTC-UTC( k )] reported in section 1 of Circular T . We show that it solves several limitations of the current method used to evaluate the uncertainties. In particular it facilitates the introduction of correlations, it

    更新日期:2020-10-30
  • Calibrating spectrometers for measurements of the spectral irradiance caused by solar radiation
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    Carsten Schinke, Hendrik Pollex, David Hinken, Martin Wolf, Karsten Bothe, Ingo Kröger, Saulius Nevas and Stefan Winter

    Measuring the spectral irradiance of solar radiation is required in many fields of science and technology. In this work, we present an in-depth discussion of the measuring procedure and required corrections for such measurements. We also describe our measurement uncertainty analysis, which is based on a Monte-Carlo procedure in accordance with the Guide to the expression of uncertainty in measurement

    更新日期:2020-10-30
  • Benchmarking the success of CCQM key comparisons for metrology institutes and their stakeholders
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    Paul J Brewer and Richard J C Brown

    Key comparisons provide the means to assess the comparability of measurement capabilities at National Metrology Institutes and Designated Institutes worldwide. In addition, they provide a snapshot of the state of the art in measurement science and inform advances in metrology. Key comparisons provide essential information on assessing whether the metrology community can meet the needs of stakeholders

    更新日期:2020-10-30
  • A strontium optical lattice clock with 1 × 10 −17 uncertainty and measurement of its absolute frequency
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    Richard Hobson, William Bowden, Alvise Vianello, Alissa Silva, Charles F A Baynham, Helen S Margolis, Patrick E G Baird, Patrick Gill and Ian R Hill

    We present a measurement of the absolute frequency of the 5 s 2 1 S 0 to 5s5p 3 P 0 transition in 87 Sr which is a secondary representation of the SI second. We describe the optical lattice clock apparatus used for the measurement, and we focus in detail on how its systematic frequency shifts are evaluated with a total fractional uncertainty of 1 × 10 −17 . Traceability to the International System

    更新日期:2020-10-30
  • Spaceborne radiance temperature standard blackbody for Chinese high-precision infrared spectrometer
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    Xiaopeng Hao, Jian Song, Lei Ding, Ping Wen, Jianping Sun, Yang Liu, Zundong Yuan, Yuning Duan and Yong Zhang

    As a radiance temperature standard source for the Chinese high-resolution spectrum infrared spectrometer, the National Institute of Metrology, China, developed a spaceborne radiance temperature standard blackbody (SRTSB) combined with a series of miniature phase change fixed points (MPCFPs) for temperature calibration and emissivity verification using a thermal radiation loop (TRL). The MPCFPs of the

    更新日期:2020-10-30
  • Quantification of single-strand DNA by sequence-specific counting in capillary flow cytometry
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    Hee-Bong Yoo, Chaeeun Lee, Kee-Suk Hong, Sang-Ryoul Park and Inchul Yang

    In this study, we report an approach to achieve sequence-specific counting of single DNA molecules, which is required for more versatile applications of the previously reported absolute DNA quantification technique based on flow cytometric DNA single molecule counting. While using the same capillary-based flow cytometric setup, fluorescence activation of a target DNA was made with a number of fluorescent

    更新日期:2020-10-30
  • Establishment of 2π total spectral radiant flux scale with a broadband LED-based transfer standard source
    Metrologia (IF 2.28) Pub Date : 2020-10-29
    Yuri Nakazawa, Kenji Godo, Kazuki Niwa, Tatsuya Zama, Yoshiki Yamaji and Shinya Matsuoka

    The National Metrology Institute of Japan realized a total spectral radiant flux scale in the visible wavelength range (from 380 nm to 780 nm) for sphere-spectroradiometer calibration in 2π geometry. For a transfer standard in 2π geometry, a standard source based on a specially-designed broadband light-emitting diode (2π standard LED) was used. For the scale realization, we used the goniophotometer/spectroradiometer

    更新日期:2020-10-30
  • A generalizable formalism for computing uncertainties in UTC
    Metrologia (IF 2.28) Pub Date : 2020-10-28
    Demetrios Matsakis

    Algorithms to compute the statistical and systematic uncertainties in the difference between Coordinated Universal Time (UTC) and individual laboratory UTC realizations were published in several different, but equivalent, forms the early twenty-first century, at a time when the UTC algorithm was based on a minimal network. In this paper we extend the theory to compute the uncertainties in a manner

    更新日期:2020-10-30
  • Measurement of thermodynamic temperature between 5 K and 24.5 K with single-pressure refractive-index gas thermometry
    Metrologia (IF 2.28) Pub Date : 2020-10-18
    Bo Gao, Haiyang Zhang, Dongxu Han, Changzhao Pan, Hui Chen, Yaonan Song, Wenjing Liu, Jiangfeng Hu, Xiangjie Kong, Fernando Sparasci, Mark Plimmer, Ercang Luo and Laurent Pitre

    We describe measurements of thermodynamic temperature in the range 5 K to 24.5561 K (the triple point of neon) using single-pressure refractive-index gas thermometry (SPRIGT) with 4 He. In the wake of the May 2019 re-definition of the kelvin and its associated mise en pratique , the main purpose of the work is to provide values of T – T 90 , the discrepancy between thermodynamic temperature and that

    更新日期:2020-10-19
  • Correction factors for two new reference beta radiation fields
    Metrologia (IF 2.28) Pub Date : 2020-10-14
    R Behrens

    Several correction factors for two new reference beta-particle radiation fields complementing ISO 6980 have been measured and calculated for both primary beta dosimetry and the operational quantities in radiation protection. The following correction factors for primary beta dosimetry for the determination of the absorbed dose to tissue, D t , have been determined by calculations: k ba for backscatter

    更新日期:2020-10-16
  • A novel method for simultaneous measurement of thickness, refractive index, bow, and warp of a large silicon wafer using a spectral-domain interferometer
    Metrologia (IF 2.28) Pub Date : 2020-10-14
    Jungjae Park, Jaeseok Bae, Yoon-Soo Jang and Jonghan Jin

    In this study, an optical system for simultaneous measurement of physical thickness, group refractive index, bow, and warp of a large silicon wafer is first proposed based on a reflection-type spectral-domain interferometer. Such key parameters are determined by combining four different optical path differences (OPDs) measured at each sampling point throughout two-axis sample scanning within area of

    更新日期:2020-10-16
  • Enhancing the parameter estimation precision in a damped system by square-wave modulation
    Metrologia (IF 2.28) Pub Date : 2020-10-14
    DuoJia Wang, Xin Li and Yu Wang

    The quantum Fisher information (QFI) plays a key role in quantum metrological scenarios, and can be enhanced by certain entanglement protocols. In this work, we focus on the maximal mean QFI for L qubits, and study how a dynamical decoupling scheme rescues the entanglement-assisted QFI, which would be rapidly damaged by decoherence without such a scheme. We found that the square-wave modulation for

    更新日期:2020-10-16
  • Measuring atom positions in a microwave cavity to evaluate distributed cavity phase shifts
    Metrologia (IF 2.28) Pub Date : 2020-10-14
    K Burrows, R J Hendricks, K Szymaniec, K Gibble, S Beattie and B Jian

    Distributed cavity phase (DCP) frequency shifts are a leading systematic effect in atomic fountain frequency standards. They originate from the phase variations of the field in the microwave cavity combined with different positions of the atoms in the cavity on the ascent and descent. Here we demonstrate techniques to precisely determine the position of the cloud of atoms in the microwave cavity, using

    更新日期:2020-10-16
  • Linearity of a silicon carbide photodiode in the deep-UV spectral region: implications on Doppler broadening thermometry
    Metrologia (IF 2.28) Pub Date : 2020-10-14
    Hemanth Dinesan, Stefania Gravina, Cecilia Clivati, Antonio Castrillo, Filippo Levi and Livio Gianfrani

    The linearity of the responsivity of a silicon carbide photodetector in the deep-ultraviolet has been studied using a variant of the so-called intensity-ratio method in view of the implementation of low-uncertainty Doppler-broadening thermometry in mercury vapours. To this purpose, coherent radiation at the wavelength of 254 nm has been produced by means of non-linear mixing of two visible laser beams

    更新日期:2020-10-16
  • What is a mole?
    Metrologia (IF 2.28) Pub Date : 2020-10-14
    Richard J C Brown and Paul J Brewer

    The mole was the final base unit to be included in the International System of Units. This article explores: our understanding of the mole and its characteristics; its relationship with the base quantity, amount of substance, of which it is the base unit; and when alternative ways of expressing measurement results would be preferable. Importantly, since the SI is a practical system, this article also

    更新日期:2020-10-16
  • Calibration of outer diameter standards (EURAMET.L-K4 2005.1)
    Metrologia (IF 2.28) Pub Date : 2020-10-08
    R Koops, R Bergmans and G Kotte

    At its meeting in October 2013, the EURAMET TC-L, decided upon a follow up comparison of the EUROMET.L-K4.2005 key comparison on diameter standards. This as a response to the executive report of the EUROMET.L-K4.2005 which contains several corrective actions to be performed for the following participants: INRIM, MIRS, NPL, SMD and VSL. == Main text To reach the main text of this paper, click on Final

    更新日期:2020-10-12
  • Bilateral comparison of 10 pF and 100 pF standards (ongoing BIPM key comparisons BIPM.EM-K14.a and 14.b) between the SASO (Saudi Arabia) and the BIPM
    Metrologia (IF 2.28) Pub Date : 2020-10-07
    J A Moreno, P Gournay and A AlAyli

    This report presents the results of a bilateral comparison between the SASO, Saudi Arabia, and the BIPM, which was carried out using two 10 pF and two 100 pF travelling standards belonging to the BIPM following an "A-B-A" pattern. The comparison at 10 pF forms part of the ongoing BIPM key comparison BIPM.EM-K14.a and that at 100 pF of the ongoing BIPM key comparison BIPM.EM-K14.b, where BIPM is the

    更新日期:2020-10-08
  • Qualification and frequency accuracy of the space-based primary frequency standard PHARAO
    Metrologia (IF 2.28) Pub Date : 2020-10-01
    Ph Laurent, F X Esnaut, K Gibble, P Peterman, T Lévèque, Ch Delaroche, O Grosjean, I Moric, M Abgrall, D Massonnet and Ch Salomon

    The flight model of the laser-cooled cesium atomic clock, PHARAO, has been qualified for operation in space. The clock has passed the vibration, thermal and electromagnetic compatibility tests required to fly in low Earth orbit (400 km). On the ground, the clock realized a typical frequency stability of 3.0 × 10 −13 τ −1/2 with an estimated accuracy of 2.3 × 10 −15 . Frequency comparisons with the

    更新日期:2020-10-02
  • Update of the BIPM comparison BIPM.RI(II)-K1.Na-22 of activity measurements of the radionuclide 22 Na to include the 2014 result of the LNE-LNHB (France)
    Metrologia (IF 2.28) Pub Date : 2020-09-30
    C Michotte, G Ratel, S Courte, R Coulon, S Judge, C Fréchou, C Bobin, P Cassette, I Tartés and C Thiam

    Since 1976, 13 laboratories have submitted 29 samples of 22 Na 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 LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each

    更新日期:2020-10-02
  • Final report for GULFMET.M.M-K4: key comparison of 1 kg stainless steel mass standards
    Metrologia (IF 2.28) Pub Date : 2020-09-30
    Beste Korutlu, Christos Mitsas, Andrea Malengo, Christian Wüthrich, Sungjun Lee, Saud Alqarni, Aisha Al-Abdulhadi, Abeer I Al-Qattan and Khalid Sadee Mahmoud

    This report summarizes the results of the key comparison (KC) carried out among eight National Metrology Institutes (NMIs) and an Accredited Calibration Laboratory, six of which are member countries of Gulf Association for Metrology (GULFMET). The KC of two 1 kg stainless steel knob weights was decided during the 11th meeting of GULFMET TC Mass held in Abu Dhabi, 2017. TÜBİTAK UME (Turkey) acted as

    更新日期:2020-10-02
  • EURAMET key comparison 1031 (EURAMET.M.D-K1.1)—solid density comparison
    Metrologia (IF 2.28) Pub Date : 2020-09-30
    Horst Bettin, Michael Borys, Martin Firlus, Christian Buchner, Zoltan Zelenka, Nieves Medina, Tijana Parlić-Risović, Mladen Bezjak, Chris Mitsas, Alexandros Lefkopoulos, Elżbieta Lenard, George Florian Popa, Andrea Malengo, Tanguy Madec, Florian Beaudoux, Peter Fuchs, Kilian Marti, Christian Wüthrich, Heikki Kajastie, Alaaeldin A Eltawil, Ken-ichi Fujii, Naoki Kuramoto, Atsushi Waseda, Michael Perkin

    The results are presented of the key comparison EURAMET 1031 (EURAMET.M.D-K1.1) that covered the measurements of density and volume of silicon spheres of three different masses at 20 °C and 101325 Pa. The volume and density determinations of 15 national metrology institutes (NMIs) were checked and linked to the CCM.D-K1 key comparison. The measurements were carried out near 20 °C and at atmospheric

    更新日期:2020-10-02
  • Angles in the SI: treating the radian as an independent, unhidden unit does not require the redefinition of the term ‘frequency’ or the unit hertz
    Metrologia (IF 2.28) Pub Date : 2020-09-24
    Paul Quincey

    Some recent papers have argued that frequency should have the dimensions of angle/time, with the consequences that 1 Hz = 2π rad s −1 instead of 1 s −1 , and also that ν = ω and h = ħ . This letter puts the case that this argument redefines the quantity ‘frequency’ and then draws conclusions from equations that rely on the standard definition being used. The problems that this redefinition is designed

    更新日期:2020-09-25
  • Artifacts and errors in cross-spectrum phase noise measurements
    Metrologia (IF 2.28) Pub Date : 2020-09-24
    Yannick Gruson, Adrian Rus, Ulrich L Rohde, Alexander Roth and Enrico Rubiola

    This article deals with the erratic and inconsistent phase-noise spectra often seen in low-noise oscillators, whose floor is of the order of −180 dBc/Hz or less. Such oscillators are generally measured with two-channel instruments based on averaging two simultaneous and statistically independent measures. Our new method consists of inserting a dissipative attenuator between the oscillator under test

    更新日期:2020-09-25
  • Comparisons of national standards in the field of gas flow rate and volume, gas flow rates from 20 to 6500 m 3 /h
    Metrologia (IF 2.28) Pub Date : 2020-09-16
    A V Mingaleev, A B Yakovlev, B Mickan, A I Bardonov, D Serediuk, A Stankevicius and I Busuladz̆ić

    The supplementary international comparison of national gas flow standards COOMET.M.FF-S9 was carried out from May 2019 to January 2020. The comparison were made in the range of gas flow from 20 to 6500 m 3 /h. Six European National Metrological Institutes (VNIIM-VNIIR, PTB, IFSM, BelGIM, LEI and LABSAGAS) took part in the comparison. The VNIIM-VNIIR acted as a pilot laboratory. The participants used

    更新日期:2020-09-18
  • Final Report of COOMET.M.H-S5
    Metrologia (IF 2.28) Pub Date : 2020-09-16
    V Skliarov, J Dovshenko, F Menelao, J Borovský, N Kamkova, E Obozny and M Zhamanbalin

    This report describes the results of comparison COOMET.M.H-S5. The comparison measurements between the five participants NSC "IM" (pilot laboratory), PTB, CMI, BelGIM, RSE "KazInMetr" were started in November 2013 and ended in May 2015. In the RMO SC, one set of hardness reference blocks were used consisting of 5 (five) blocks of the Rockwell scales and hardness levels 80-86 HRA, 80-100 HRBW, 20-30

    更新日期:2020-09-18
  • Calibration of ultrastable low-noise current amplifiers without direct use of a cryogenic current comparator
    Metrologia (IF 2.28) Pub Date : 2020-09-06
    M Götz, D Drung, C Krause and Mortara A

    The established calibration of the transresistance of the ultrastable low-noise current amplifier (ULCA) directly involves a cryogenic current comparator (CCC). Here, we present an alternative approach based on a calibrated set of three resistors and three digital voltmeters. This approach was experimentally verified for a two-channel ULCA with nominally 1 GΩ transresistance using PTB’s travelling

    更新日期:2020-09-08
  • Radiometric characterization of a triggered narrow-bandwidth single-photon source and its use for the calibration of silicon single-photon avalanche detectors
    Metrologia (IF 2.28) Pub Date : 2020-09-06
    Hristina Georgieva, Marco López, Helmuth Hofer, Justus Christinck, Beatrice Rodiek, Peter Schnauber, Arsenty Kaganskiy, Tobias Heindel, Sven Rodt, Stephan Reitzenstein and Stefan Kück

    The traceability of measurements of the parameters characterizing single-photon sources, such as photon flux and optical power, paves the way towards their reliable comparison and quantitative evaluation. In this paper, we present an absolute measurement of the optical power of a single-photon source based on an InGaAs quantum dot under pulsed excitation with a calibrated single-photon avalanche diode

    更新日期:2020-09-08
  • Precise measurements of super-high reflectance with cavity ring-down technique
    Metrologia (IF 2.28) Pub Date : 2020-09-06
    Shilei Xiao, Bincheng Li and Jing Wang

    The precise measurements of absolute high, especially super-high reflectances (R > 99.999%) of highly reflective mirrors with cavity ring-down (CRD) technique is challenging due to lack of ‘known’ calibration samples and eligible and effective cross-validation method. In this paper, measurement precision of super-high reflectance is greatly improved via filtering out the random optical loss fluctuation

    更新日期:2020-09-08
  • Realization of the kilogram using the KRISS Kibble balance
    Metrologia (IF 2.28) Pub Date : 2020-09-06
    Dongmin Kim, MyeongHyeon Kim, Minky Seo, Byung-Chill Woo, Sungjun Lee, Jong-Ahn Kim, Dong-Hun Chae, Mun-Seog Kim, In-Mook Choi and Kwang-Cheol Lee

    In the revised international system of units (SI), the kilogram is realized through methods linking mass to the Planck constant such as the Kibble balance experiment and x-ray crystal density method. We report on the first experiment for kilogram realization at the Korea Research Institute of Standards and Science (KRISS). The masses of two artefacts (platinum–iridium and stainless steel) were measured

    更新日期:2020-09-08
  • An optimized sampling system for highly reproducible isotope ratio measurements ( δ 13 C and δ 18 O) of pure CO 2 gas by infrared spectroscopy
    Metrologia (IF 2.28) Pub Date : 2020-09-06
    Joële Viallon, Edgar Flores, Philippe Moussay, Ian Chubchenko, Francesca Rolle, Tiqiang Zhang, Eric B Mussell Webber and Robert I Wielgosz

    The characteristics of an optimized sampling system for measurements of isotope ratios in pure CO 2 gas with Isotope Ratio Infrared Spectroscopy measurement systems that has achieved reproducible measurement of δ 13 C and δ 18 O values with 0.02‰ reproducibility (1 σ) is described. The key elements of the sampling system revolve around almost identical treatment of sample and reference gases allowing

    更新日期:2020-09-08
  • The upgrade of NIM-2 joule balance since 2017
    Metrologia (IF 2.28) Pub Date : 2020-09-06
    Zhengkun Li, Yang Bai, Jinxin Xu, Yunfeng Lu, Pengcheng Hu, Yongmeng Liu, Dawei Wang, Qiang You, Lushuai Qian, Zhonghua Zhang, Qing He and Jiubin Tan

    In 2017, we published the first measurement result with the NIM-2 joule balance and the relative standard uncertainty was 2.4 × 10 −7 . Since then, a series of improvements have been carried out to upgrade the NIM-2 joule balance towards the 10 –8 level relative uncertainty. The main improvements include a permanent magnet, as well as a two-layer magnetic shield to decrease the main uncertainty contribution

    更新日期:2020-09-08
  • Characterization of a newly developed diaphragmless shock tube for the primary dynamic calibration of pressure meters
    Metrologia (IF 2.28) Pub Date : 2020-09-06
    A Svete and J Kutin

    In conventional shock tubes with a diaphragm, many effects related to the burst of the diaphragm can influence shock formation, thus preventing an ideal pressure step change, as predicted by the shock tube measurement model being generated. This paper presents a newly developed diaphragmless shock tube with a quick-acting pneumatic valve, which demonstrates several advantages over conventional shock

    更新日期:2020-09-08
  • Thermodynamic-temperature data from 30 K to 200 K
    Metrologia (IF 2.28) Pub Date : 2020-09-06
    Christof Gaiser, Bernd Fellmuth and Norbert Haft

    New measurements of thermodynamic temperature T with Dielectric-Constant Gas Thermometry (DCGT) were performed at PTB from 50 K to 200 K. Particular care was taken to check for possible systematic sources of errors by performing experiments applying three working gases, namely helium, neon, and argon, the polarizability of which differs by a factor of up to eight. Together with former DCGT values of

    更新日期:2020-09-08
  • Calibration of 1-D CMM artefacts: step gauges (EURAMET.L-K5.2016)
    Metrologia (IF 2.28) Pub Date : 2020-08-27
    Tim Coveney, Michael Matus, Shihua Wang, Ville Byman, Antti Lassila, Nasser Alqahtani, Faisal Alqahtani, Dean Sumner, Jürg Spiller, Felix Meli, Gian Bartolo Picotto, Roberto Bellotti, Osamu Sato, Rina Sharma, Girija Moona, Vinod Kumar, Joaquín Rodríguez, Emilio Prieto, İlker Meral, Okhan Ganioğlu, José Salgado, Adam Wójtowicz, Pavel Skalník, Vít Zelený, John Stoup, Gerard Kotte, Richard Koops, Edgar

    The results of the inter-RMO key comparison EURAMET.L-K5.2016 on the calibration of a step gauge are reported. Twenty-two National Metrology Institutes from four different metrological regions all over the world participated in this comparison which lasted three years, from December 2015 to December 2018. Two artefacts were circulated so that the varying ranges of participants equipment could be accommodated

    更新日期:2020-08-28
  • Final report for international comparison APMP.QM-S12: BTEX in nitrogen at 100 nmol/mol
    Metrologia (IF 2.28) Pub Date : 2020-08-27
    S Lee, J H Kang, Y D Kim, D H Kim, S Uehara, D Akima, N Onozawa, B Zhe, D Wang, N G Ntsasa, N Leshabane, M Jozela and J Tshilongo

    Benzene, toluene, ethylbenzene, o -xylene, m -xylene, and styrene (subsequently referred to gas BTEX) are volatile organic compounds emitted from gasoline, fossil fuel combustion, paints, rubber products, and adhesives. Exposure to BTEX can make adverse health effects on humans. Therefore, BTEX in both ambient and indoor air is regulated and monitored to protect public health. For this supplementary

    更新日期:2020-08-28
  • Bilateral key comparison CCT-K6.2 on humidity standards in the frost-point temperature range from −80 °C to −30 °C
    Metrologia (IF 2.28) Pub Date : 2020-08-27
    Christopher Meyer and Hisashi Abe

    A Consultative Committee on Thermometry (CCT) Key Comparison of frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the National Metrology Institute of Japan (NMIJ, Japan) between December 2015 and November, 2016. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and NMIJ/AIST

    更新日期:2020-08-28
  • BIPM comparison BIPM.RI(II)-K1.Ge-68 of activity measurements of the radionuclide 68 Ge for the LNMRI/IRD, NIST, NIM, IRA-METAS, LNE-LNHB and the TAEK, and the linked 2015 CCRI(II)-K2.Ge-68 comparison
    Metrologia (IF 2.28) Pub Date : 2020-08-06
    C Michotte, G Ratel, S Courte, M Nonis, A Iwahara, C J Da Silva, R Fitzgerald, D E Bergeron, J T Cessna, L Laureano-Pérez, L Pibida, B E Zimmerman, M Zhang, J Liang, H Liu, F Juget, Y Nedjadi, C Fréchou, C Bobin, E Yeltepe and A Dirican

    This report summarises the results for the new BIPM.RI(II)-K1.Ge-68 comparison. Six metrology institutes have participated, enabling the first value of the key comparison reference value(KCRV) to be determined. The KCRV was calculated using the power-moderated weighted mean and the results. A link has been made to the CCRI(II)-K2.Ge-68 comparison held in 2015 through the NIST, NIM,IRA-METAS and the

    更新日期:2020-08-10
  • Direct comparisons of European primary and secondary frequency standards via satellite techniques
    Metrologia (IF 2.28) Pub Date : 2020-08-04
    F Riedel, A Al-Masoudi, E Benkler, S Dörscher, V Gerginov, C Grebing, S Häfner, N Huntemann, B Lipphardt, C Lisdat, E Peik, D Piester, C Sanner, C Tamm, S Weyers, H Denker, L Timmen, C Voigt, D Calonico, G Cerretto, G A Costanzo, F Levi, I Sesia, J Achkar, J Guéna, M Abgrall, D Rovera, B Chupin, C Shi, S Bilicki, E Bookjans, J Lodewyck, R Le Targat, P Delva, S Bize, F N Baynes, C F A Baynham, W Bowden

    We carried out a 26-day comparison of five simultaneously operated optical clocks and six atomic fountain clocks located at INRIM, LNE-SYRTE, NPL and PTB by using two satellite-based frequency comparison techniques: broadband Two-Way Satellite Time and Frequency Transfer (TWSTFT) and Global Positioning System Precise Point Positioning (GPS PPP). With an enhanced statistical analysis procedure taking

    更新日期:2020-08-05
  • The determination of gravitational acceleration in the joule balance at NIM
    Metrologia (IF 2.28) Pub Date : 2020-08-04
    Jinxin Xu, Jinyang Feng, Qiyu Wang, Lishuang Mou, Zhengkun Li, Bin Han, Lushuai Qian, Ruo Hu, Shuqing Wu, Qing He and Tao Zheng

    The determination of the local acceleration of gravity at the mass position is an important aspect of the joule balance. Since a simultaneous measurement of the absolute gravity at the mass position with the joule balance in place is impossible, seven gravity reference sites are chosen in the joule balance laboratory. Absolute and relative gravity measurements at the reference sites were performed

    更新日期:2020-08-05
  • New apparatus for liquids high-pressure density measurement
    Metrologia (IF 2.28) Pub Date : 2020-08-04
    Andreia Furtado, Frank Lorenz and Henning Wolf

    Nowadays, fast and precise density measurements of fluids are mostly performed using so-called oscillation-type density meters, able to measure in a very wide interval of temperature and pressure. This work aimed to developed, characterized and validated a high-pressure density measurement (HPDM) apparatus ensuring the traceability to SI of density measurements performed with these devices at high

    更新日期:2020-08-05
  • Measurement of groove depth standards in the range 1 μm up to 1 mm (EURAMET project 1407)
    Metrologia (IF 2.28) Pub Date : 2020-08-03
    Uwe Brand, Michael Matus, Laura Carcedo, Lukasz Slusarski, Gian Bartolo Picotto, Antti Lassila, Faith Hungwe, Olena Flys, Murat Aksulu and Vladimir Kosteev

    A comparison measurement between 10 national metrology institutes on two types of depth setting standards was conducted using mostly tactile but also two optical instruments for measurement. Three etched silicon standards with depths of 5, 20 and 50 μm and one diamond turned nickel coated copper standard with depths of 200, 600 and 900 μm were measured. The cross section of the grooves was trapezoidal

    更新日期:2020-08-04
  • CCQM-K146 low-polarity analyte in high fat food: benzo[a]pyrene in olive oil
    Metrologia (IF 2.28) Pub Date : 2020-08-03
    Xiaomin Li, Hongmei Li, Qinghe Zhang, Xiaohua Lu, Shuangqing Li, Matthias Koch, Joachim Polzer, Rudolf Hackenber, Md Moniruzzaman, Mala Khan, Elias Kakoulides, Kong Pak-wing, Richy, Ng Chi-shing, Ting Lu, Ee Mei Gui, Pui Sze Cheow, Tang Lin Teo, Eliane Rego, Bruno Garrido, Lucas Carvalho, Rodrigo Leal, Fernando Violante, Song-Yee Baek, Sunyoung Lee, Kihwan Choi, Byungjoo Kim, Milena Bucar-Miklavcic

    The demonstration of competency and equivalence for the assessment of levels of contaminants and nutrients in primary foodstuffs is a priority within the 10-year strategy for the CCQM Organic Analysis WG series of Track A core comparisons. The area of low polarity analytes in high fat foods had not been covered by the OAWG for many years since the key comparison CCQM-K21 p,p'-DDT in fish oil occurring

    更新日期:2020-08-04
  • Pilot comparison CCQM-P177—monoterpenes in nitrogen at 2.5 nmol mol −1 final report
    Metrologia (IF 2.28) Pub Date : 2020-08-03
    Christina Liaskos, George Rhoderick, Joseph Hodges, Antonio Possolo and Olaf Wilke

    Growing awareness of the impact of monoterpenes on climate, atmospheric chemistry, and indoor air quality has necessitated the development of measurement standards to globally monitor and control their emissions. For National Metrology Institutes to develop such standards, it is essential that they demonstrate measurement equivalence for assigned values at the highest levels of accuracy. This report

    更新日期:2020-08-04
  • Key comparison study—organic solvent calibration solution—gravimetric preparation and value assignment of trans-zearalenone (trans-ZEN) in acetonitrile (ACN)
    Metrologia (IF 2.28) Pub Date : 2020-08-03
    R D Josephs, A Daireaux, M Bedu, Xiuqin Li, Xiaomin Li, Z Guo, T Choteau, G Martos, S Westwood, R I Wielgosz, H Li, M Simón, E C P do Rego, B C Garrido, R Leal, L Carvalho, E Guimarães, A Bahadoor, J Bates, J E Melanson, P Giannikopoulou, C Alexopoulos, E Kakoulides, I Mugenya, D Prevoo-Franzsen, M Fernandes-Whaley, S Marbumrung, M Bilsel, B Binici and T Gokcen

    The CCQM-K154.a and subsequent CCQM-K154.a.1 comparisons were coordinated by the the Bureau International des Poids et Mesures (BIPM) and the Chinese National Institute of Metrology (NIM) on behalf of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) for National Measurement Institutes (NMIs) and Designated Institutes (DIs) which provide measurement

    更新日期:2020-08-04
  • Key comparison EURAMET.PR-K2.a.2011—spectral responsivity in the range of 900 nm to 1600 nm
    Metrologia (IF 2.28) Pub Date : 2020-08-02
    Steven van den Berg, Paul Dekker, Subrena Harris, Teresa Goodman, Marek Šmíd, Grzegorz Szajna, Jarle Gran, Anne Andersson, Stefan Källberg, Özcan BAZKIR and Seval MERIC

    The Euramet.PR-K2.a comparison on spectral responsivity for the wavelength range 900 nm to 1600 nm, as described in this report, was carried out to establish the degree of equivalence for the participating European laboratories with respect to the Key Comparison Reference Value (KCRV) of the CCPR-K2.a-2003 comparison. Seven laboratories, including pilot and link laboratory, participated. The comparison

    更新日期:2020-08-03
  • Pneumatic gauge pressure comparison from 700 kPa to 7 000 kPa
    Metrologia (IF 2.28) Pub Date : 2020-08-02
    Leonardo De la Cruz, Jorge Torres, Adrián Solano, Marcial Espinoza, Maria Neyra, Pablo Constantino, Jesús Aranzolo and Ricardo Sánchez

    This report presents the final results of the supplementary comparison SIM.M.P-S10 for pneumatic gauge pressure from 700 kPa to 7 000 kPa. This comparison was carried out in the period from November 2014 to January 2015, by using a digital pressure manometer with uncertainty 0.010 % of the reading as the transfer standard for the comparison. The reference value for this comparison was given by the

    更新日期:2020-08-03
  • Pilot study on peptide purity—synthetic oxytocin
    Metrologia (IF 2.28) Pub Date : 2020-08-02
    R D Josephs, M Li, A Daireaux, T Choteau, G Martos, S Westwood, R I Wielgosz, H Li, S Wang, L Feng, T Huang, M Pan, T Zhang, N Gonzalez-Rojano, M Balderas-Escamilla, A Perez-Castorena, M Perez-Urquiza, I Ün, and M Bilsel

    Under the auspices of the Protein Analysis Working Group (PAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a pilot study, CCQM-P55.2.b, was coordinated by the Bureau International des Poids et Mesures (BIPM) and the Chinese National Institute of Metrology (NIM). Three Metrology Institutes or Designated Institutes and the BIPM participated. Participants were required to assign the

    更新日期:2020-08-03
  • Comparisons of air kerma and absorbed dose to water standards in Co-60 radiation beams for radiotherapy
    Metrologia (IF 2.28) Pub Date : 2020-07-30
    Christian Kottler, Andreas Steurer, Frank Delaunay, Jacco de Pooter, Cristina García Mulas and Liviu-Cristian Mihailescu

    The air kerma and absorbed dose to water standards for 60Co radiotherapy beams of 6 EURAMET NMIs were compared by circulating 2 transfer standards. The schedule for the measurements lasted from March 2013 to February 2015. The participants determined the calibration coefficients for the 2 transfer standards in both radiation quantities mentioned above. The comparison results are given in terms of air

    更新日期:2020-08-01
  • GULFMET key comparison of DC voltage at 1.018 V and 10 V
    Metrologia (IF 2.28) Pub Date : 2020-07-26
    Steven Yang, CM Tsui, Stephane Solve, Kyu-Tae Kim, Srdan Calija, Jon Bartholomew and Abdullah Alrobaish

    This report presents the GULFMET key comparison (GULFMET.EM.BIPM-K11) results of DC voltages at the 1.018 V and 10 V with two travelling electronic DC reference standards. This comparison was supported by the BIPM and GULFMET associate members, KRISS and SCL, which are from the APMP. The linking difference from the BIPM.EM-K11 KCRV was calculated. The agreement between participating laboratories is

    更新日期:2020-07-27
  • Final report on key comparison EURAMET.AUV.V-K2
    Metrologia (IF 2.28) Pub Date : 2020-07-26
    Joanna Kolasa and Daniela Virovska

    This final report describes the results obtained in a key comparison of primary vibration calibration facilities. Two piezoelectric standard accelerometers (one single-ended as well one back-to-back type) were calibrated first at Central Office of Measures (GUM), acting as pilot and linking laboratory, and Bulgarian Institute for Metrology (BIM). The results of the BIM obtained in this comparison were

    更新日期:2020-07-27
  • Calibration of thermocouples from 419,527 °C (freezing point of Zn) up to 1492 °C (melting point of the Pd-C eutectic), by the temperature fixed point and comparison methods
    Metrologia (IF 2.28) Pub Date : 2020-07-26
    D del Campo, Y Abdelaziz, M Anagnostou, N Arifovic, R A Bergerud, J Bojkovski, E Ciocarlan, F Edler, C Elliot, O Hathela, N Hodzic, M Holmsten, L Iacomini, M Kozicki, S Nedialkov, M Sadli, S Simic, R Strnad and E Turzó-András

    This report present the results of the EURAMET inter-comparison carried out to compare the calibration of thermocouples from 419,527 °C (freezing point of Zn) up to 1492 °C (melting point of the Pd-C eutectic). This inter-comparison is intended to be used to support the calibration and measurement capabilities (CMCs) of the participants in the calibration of thermocouples. The comparison was organized

    更新日期:2020-07-27
  • Final report on supplementary comparison of national standards for liquid flow COOMET.M.FF-S2 (COOMET Project 406/UA/07)
    Metrologia (IF 2.28) Pub Date : 2020-07-26
    E Frahm, B Mickan, V Gulyuk, G Reut, G Zigmantas, M Benkova and M Kayumov

    A supplementary comparison, COOMET.M.FF-S2, in the field of water flow was organized by the COOMET Technical Committee (TC) 1.4 Flow Measurement. The goal of the comparison was to confirm the calibration and measurement capabilities (CMC) of the participating national metrology institutes (NMIs) in the flow ranges between 0.5 m 3 /h and 5.0 m 3 /h, and, respectively, between 20.0 m 3 /h and 100.0 m

    更新日期:2020-07-27
  • Gravity and anisotropy effects in the volume determination of Si spheres for the kilogram realisation
    Metrologia (IF 2.28) Pub Date : 2020-07-12
    D Mari, A Nicolaus, E Kuhn, N Kuramoto, G Mana and E Massa

    The counting of 28 Si atoms plays a fundamental role in the realisation of the unit of mass in terms of stipulated values of fundamental physical constants. In this realisation, the measurement of the volume of a 28 Si sphere is a fundamental step. This paper reports a finite element analysis of the self-weight effect on the volume determination, taking the crystal anisotropy into account. The sphere

    更新日期:2020-07-13
  • Accounting for polarization–related effects in the measurement of the bidirectional reflectance distribution function
    Metrologia (IF 2.28) Pub Date : 2020-07-12
    A Calderón, A Ferrero and J Campos

    When measuring the Bidirectional Reflectance Distribution Function (BRDF) to characterize typical materials, the effect of the polarization of the light source or the dependence of the detector on the polarization is not usually considered, even though many studies have proven their impact in the uncertainty of the BRDF of most materials, including diffuse reflectance standards. A methodology to assess

    更新日期:2020-07-13
  • The BIPM Kibble balance for realizing the kilogram definition
    Metrologia (IF 2.28) Pub Date : 2020-07-12
    H Fang, F Bielsa, S Li, A Kiss and M Stock

    After several years of development and continuous improvement of the BIPM Kibble balance, mass measurement of a 1 kg Pt/Ir artefact in terms of the Planck constant has been carried out. The paper describes the apparatus and its alignment, and explains the measurement and data processing. The balance operates in a one-mode and two measurement phase scheme using a bifilar coil. The mass value of the

    更新日期:2020-07-13
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