Metrologia最新文献

{"title":"Supplementary comparison of the measurement of current transformers (CTs)","authors":"A A Akhmeev, E V Voronskay, V N Kikalo, E V Melkumyan, O Dzhasinbekov, G Gantumur, D M Volozhinskii","doi":"10.1088/0026-1394/61/1a/01006","DOIUrl":"https://doi.org/10.1088/0026-1394/61/1a/01006","url":null,"abstract":"<title>Main text</title>The purpose of conducting comparison COOMET.EM-S22 of reference measuring systems of the AC current ratio of national metrological institutes (NMIs) is to determine the degree of consistency of national standards among themselves in the participating countries.Six NMIs participated in the supplementary comparison COOMET.EM-S22. Affiliated Branch of D I Mendeleev Institute for Metrology (VNIIM-UNIIM), Russian Federation, acted as the coordinating laboratory of the comparison.The comparisons were carried out by comparing the measurement results of the characteristics of measuring current transformers (CTs), namely, the units of the coefficient and the angle of the scale conversion of the sinusoidal current at a frequency of 50 Hz.To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/coomet-em-s22\" xlink:type=\"simple\">Final Report</ext-link>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <ext-link xlink:href=\"https://www.bipm.org/kcdb/\" xlink:type=\"simple\">https://www.bipm.org/kcdb/</ext-link>.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum plasmonic sensing by Hong–Ou–Mandel interferometry","authors":"Seungjin Yoon, Yu Sung Choi, Mark Tame, Jae Woong Yoon, Sergey V Polyakov and Changhyoup Lee","doi":"10.1088/1681-7575/ad61ea","DOIUrl":"https://doi.org/10.1088/1681-7575/ad61ea","url":null,"abstract":"We propose a quantum plasmonic sensor using Hong–Ou–Mandel (HOM) interferometry that measures the refractive index of an analyte, embedded in a plasmonic beam splitter composed of a dual-Kretschmann configuration, which serves as a frustrated total internal reflection beamsplitter (BS). The sensing performance of the HOM interferometry, combined with single-photon detectors, is evaluated through Fisher information for estimation of the refractive index of the analyte. This is subsequently compared with the classical benchmark that considers the injection of a coherent state of light into the plasmonic BS. By varying the wavelength of the single photons and the refractive index of the analyte, we identify a wide range where a 50% quantum enhancement is achieved and discuss the observed behaviors in comparison with the classical benchmark. We expect this study to provide a useful insight into the advancement of quantum-enhanced sensing technologies, with direct implications for a wide range of nanophotonic BS structures.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141774243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Letter case pairs for SI prefix symbols","authors":"Richard J C Brown","doi":"10.1088/1681-7575/ad6324","DOIUrl":"https://doi.org/10.1088/1681-7575/ad6324","url":null,"abstract":"This letter considers the potential for confusion in the presentation and interpretation of measurement results caused by the existence of upper- and lower-case letter pairs for SI prefix symbols, an example of this being the newest prefix symbols Q & q and R & r, adopted at the 27th Meeting of the General Conference on Weights and Measures in November 2022. The requirements of digitalisation and machine readability, when making choices for new unit and prefix symbols, are also examined.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141774244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Small-Block Frequency Estimators to Control Step Size in Phase-Shifting Interferometry","authors":"I. D. Leroux, B. Eves","doi":"10.1088/1681-7575/ad6325","DOIUrl":"https://doi.org/10.1088/1681-7575/ad6325","url":null,"abstract":"\u0000 We derive an estimator for the step size in phase-shifting interferometry. Using a minimum of five samples, it avoids the occasional indeterminate results that afflict the traditional Carré step-size estimate. The estimator can be understood as a generalization of the modified-covariance frequency estimator for a real-valued sinusoid with an unknown mean. We describe its use in the NRC Gauge Block Interferometer for monitoring the motion of a phase-shifting mirror mount.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A proposal to change the leap-second adjustments to Coordinated Universal Time","authors":"Judah Levine","doi":"10.1088/1681-7575/ad6266","DOIUrl":"https://doi.org/10.1088/1681-7575/ad6266","url":null,"abstract":"\u0000 The definition of Coordinated Universal Time (UTC) in 1972 balanced the needs of the time and frequency community for a universal time scale that was traceable to the definition of frequency in the SI system of units with the needs of the astronomical community for a time scale that was closely linked to UT1, a time scale related to the rotation of Earth. The balance between these two considerations has changed very significantly since 1972, and there is widespread agreement that the method of relating UTC to UT1 should be changed by increasing the maximum tolerance between the two scales to more than the current limit of 0.9 s. We propose to realize this decision by means of an algorithmic adjustment process based on the variation in the length of the day over the previous centuries. We use these historical data to extrapolate the length of the day for a century into the future, and to compute a periodic rate adjustment to UTC based on this extrapolation. The adjustment process will not use time steps. The magnitude of the periodic rate adjustment will be re-considered every century, but the basic adjustment algorithm will not change. We suggest a maximum tolerance between UT1 and UTC that is large enough to absorb the irregular and unpredictable variations in the length of the day with respect to the long-term average increase in this value but plays no role in determining the parameters of the adjustment process that is proposed. We also propose that the adjustment be implemented at 12 UTC on 1 January or on another date that is close to a universal holiday in all time zones.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141652436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Assessment of the Ageing of the Absolute Spectral Responsivity of Trap Detectors at Krypton Ion Laser Emission Wavelengths","authors":"M. Dury, Subrena Harris, Teresa M Goodman, W. Servantes, Malcolm White","doi":"10.1088/1681-7575/ad615d","DOIUrl":"https://doi.org/10.1088/1681-7575/ad615d","url":null,"abstract":"\u0000 We have assessed the absolute spectral responsivities of three-element trap detectors calibrated against the NPL primary standard cryogenic radiometer at eight krypton ion laser emission wavelengths over an approximate period of twenty-years. As expected, we observed that the absolute spectral responsivities decrease with time. Additionally, we found that as the wavelength decreases, the ageing rate increases. At 356.4 nm, an average responsivity decrease of around -1800 ppm/year is reported. While at longer wavelengths, the slowest rate of ageing, approximately 40 ppm/year, occurs at 799.3 nm. Interestingly, the year-on-year changes exhibit a relatively linear trend, allowing us to predict the future performance of the trap detectors. It is important to note, however, that predicted performance cannot be guaranteed and regular recalibration against a primary standard is essential, especially if low calibration uncertainties are required.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141662126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accurate characterisation of optical diffuse transmission – primary facility and extension to translucent samples","authors":"J. Fu, T. Quast, S. Teichert, M. Pastuschek, Alfred Schirmacher, P. Santafé Gabarda, Kai-Olaf Hauer, Alejandro Ferrero","doi":"10.1088/1681-7575/ad615c","DOIUrl":"https://doi.org/10.1088/1681-7575/ad615c","url":null,"abstract":"\u0000 To perform accurate, high-quality and traceable measurement of optical diffuse transmission, which is quantified using the bidirectional transmittance distribution function (BTDF), a new primary facility has been developed at the Physikalisch-Technische Bundesanstalt (PTB), the German metrology institute. This newly developed reference facility will complement the available calibration services and research facilities at PTB for regular reflectance and transmittance and diffuse reflectance. The performance of the new BTDF setup has been investigated in an internal comparison, where consistency of the results was achieved. A thorough uncertainty analysis results in a minimum combined standard (k = 1) uncertainty of about 0.8 %. Research on the accurate characterisation of the BTDF of samples with non-negligible lateral scattering is being carried out on this new setup. Some first results have shown that the measured BTDF value depends on the applied irradiation area size. An empirical model has been found to describe the diffuse transmission of such translucent samples with different scattering parameters.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141659067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metrological characterization of a commercial single-photon source with high photon flux emission","authors":"H. Georgieva, Petr Stepanov, Leonora Sewidan, Anton Pishchagin, Marco A Lopez, Stefan Kueck","doi":"10.1088/1681-7575/ad615e","DOIUrl":"https://doi.org/10.1088/1681-7575/ad615e","url":null,"abstract":"\u0000 We present a comprehensive metrological characterization of a commercial single-photon source with high photon flux emission for use in radiometry. The source is based on an InGaAs quantum dot in a micropillar. A comparative analysis of two excitation schemes - phonon-assisted excitation and two-photon excitation – explores differences in excitation power dependence, temporal stability and single-photon purity. The commercial source exhibits excellent properties for the field of quantum radiometry, achieving simultaneously a photon flux of (17.19 ± 0.09) million photons/s for a pulse repetition rate of 79.4 MHz, and a single-photon purity of 98 %. Its optical power of (3.68 ± 0.02) pW is directly determined with a traceably calibrated low-noise photodiode. The ability to directly compare the photocurrent in a low-noise photodiode with the count rate at a single-photon avalanche detector allows for a seamless transition between the classical and quantum realizations of optical power. Therefore, we were able to build another bridge between classical and quantum radiometry by using a deterministic single-photon source.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141659338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calibrating the global network of gravitational wave observatories via laser power calibration at NIST and PTB","authors":"Dripta Bhattacharjee, R. Savage, Rishabh Bajpai, J. Betzwieser, V. Bossilkov, Dan Chen, Cervane Grimaud, Shingo Hido, Sudarshan Karki, Stefan Kueck, P. Lagabbe, H. Lecher, John Lehman, Francisco Llamas, Marco A Lopez, Loic Rolland, Anthony Sanchez, M. Spidell, Michelle Stephens","doi":"10.1088/1681-7575/ad615f","DOIUrl":"https://doi.org/10.1088/1681-7575/ad615f","url":null,"abstract":"\u0000 Current gravitational wave observatories rely on Photon Calibrators (Pcals) that use laser radiation pressure to generate displacement fiducials used to calibrate detector output signals. Reducing calibration uncertainty enables optimal extraction of astrophysical information such as source distance and sky position from detected signals. For the ongoing O4 observation run that started on May 24, 2023, the global gravitational wave detector network is employing a new calibration scheme with transfer standards calibrated at both the National Institute of Standards and Technology (NIST) and the Physikalisch-Technische Bundesanstalt (PTB). These transfer standards will circulate between the observatories and the metrology institutes to provide laser power calibration traceable to the International System of Units (SI) and enable assessment and reduction of relative calibration errors for the observatory network. The Laser Interferometer Gravitational-Wave Observatory (LIGO) project and the Virgo project are currently participating in the new calibration scheme. The Large-scale Cryogenic Gravitational-wave Telescope project (KAGRA) is expected to join in 2024, with the LIGO Aundha Observatory (LAO) in India joining later. Before implementing this new scheme, a NIST-PTB bilateral comparison was conducted. The results of this comparison, with significantly lower uncertainty than previous studies, are reported. We also describe the transfer of power sensor calibration, including detailed uncertainty estimates, from the transfer standards calibrated by NIST and PTB to the sensors operating continuously at the interferometer end stations. Finally, we discuss the ongoing calibration of Pcal-induced displacement fiducials for the O4 observing run. Achieved combined standard uncertainty levels as low as 0.3 % facilitate calibrating the interferometer output signals with sub-percent accuracy.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141660440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Speed of sound measurements and derived third and fourth acoustic virial coefficients of supercritical neon","authors":"Tobias Dietl, Ahmed El Hawary, Roberto M Gavioso, Robert Hellmann and Karsten Meier","doi":"10.1088/1681-7575/ad58e6","DOIUrl":"https://doi.org/10.1088/1681-7575/ad58e6","url":null,"abstract":"We report comprehensive and accurate measurements of the speed of sound in neon. These measurements were carried out by a double-path-length pulse-echo technique and cover the temperature range between 200 K and 420 K with pressures up to 100 MPa. The standard uncertainties are 1.9 mK in temperature, 22 parts in 106 in pressure and 35 parts in 106 in speed of sound. The third and fourth acoustic virial coefficients of neon were derived from the speed of sound data in the temperature range of the measurements by fitting a fourth-order acoustic virial expansion in pressure with the second acoustic virial coefficient constrained from first-principles calculations. To support our claimed uncertainty, we determined the ratio between the molar mass M and the ideal-gas heat capacity ratio of the neon sample with a relative standard uncertainty of 7.7 parts in 106 by additional speed of sound measurements using a spherical resonator at 273.16 K.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141585367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}