Pub Date : 2023-11-23DOI: 10.1088/0026-1394/60/1a/08028
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 textThis 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 measurement model was used to evaluate the coherence between these RMs, and to determine the carbon isotope delta value of each of these RMs. In general, this study shows that the 36 carbon isotope delta RMs are reliable. Further, the value assigned to the vanillin sample in this study is within 0.02 ‰ from the CCQM-K167 KCRV.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 CIPM Mutual Recognition Arrangement (CIPM MRA).
{"title":"Final report for CCQM-P212: coherence of carbon isotope delta reference materials","authors":"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","doi":"10.1088/0026-1394/60/1a/08028","DOIUrl":"https://doi.org/10.1088/0026-1394/60/1a/08028","url":null,"abstract":"<title>Main text</title>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 measurement model was used to evaluate the coherence between these RMs, and to determine the carbon isotope delta value of each of these RMs. In general, this study shows that the 36 carbon isotope delta RMs are reliable. Further, the value assigned to the vanillin sample in this study is within 0.02 ‰ from the CCQM-K167 KCRV.To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/ccqm-p212\" 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 CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"21 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138680288","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}
Pub Date : 2023-11-23DOI: 10.1088/0026-1394/60/1a/08031
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 textSupplementary 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 CIPM Mutual Recognition Arrangement (CIPM MRA).
{"title":"Supplementary comparison SIM.QM-S06 - automotive exhaust gases (CO, CO2, C3H8)","authors":"Cristiane R A C Iglesias, Andreia L Fioravante, Claudia C Ribeiro, Viviane F Mello, Rocio C T Zambrano, Steve A Acco García, Florencia Almirón","doi":"10.1088/0026-1394/60/1a/08031","DOIUrl":"https://doi.org/10.1088/0026-1394/60/1a/08031","url":null,"abstract":"<title>Main text</title>Supplementary comparison of carbon monoxide, carbon dioxide and propane in nitrogen (model 1).To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/sim-qm-s6\" 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 CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"70 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138680284","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}
Pub Date : 2023-11-23DOI: 10.1088/0026-1394/60/1a/08029
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 textThe 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 NMIs and DIs to have access to on-demand comparisons for their CO2 in air and nitrogen standards over the range 350 μmol mol−1 to 800 μmol mol−1.The pilot studies supplemented the validation activities on the BIPM reference facility already reported in CCQM-P188, and ongoing validation studies against NIST, NOAA and VSL gas standards. A description of the BIPM facility performance will be submitted for publication in a peer-reviewed journal in 2023, with a full uncertainty analysis showing that it can operate with a standard uncertainty of 0.1 μmol mol−1 over the amount fraction range of the comparison (Viallon et al 2023b).The comparison was organised using a sufficient number of independent standards, to demonstrate the performance of the BIPM system, whilst limiting the duration of the pilot study, allowing the key comparison to start as planned in 2024. Following discussions at the 44th GAWG meeting it was decided that comparisons with 3 independent standards at 3 nominal amount fraction values (380, 480 and 800 μmol mol−1) in the two matrices (air and nitrogen) would be sufficient.Results presented in this report show a good agreement between values assigned by participants and those measured at the BIPM, over the entire range of the comparison and for both matrices (air and nitrogen). The BIPM pVT−CO2 facility is ready to act as reference facility for the ongoing key comparison BIPM.QM−K2.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 CIPM Mutual Recognition Arrangement (CIPM MRA).
{"title":"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)","authors":"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","doi":"10.1088/0026-1394/60/1a/08029","DOIUrl":"https://doi.org/10.1088/0026-1394/60/1a/08029","url":null,"abstract":"<title>Main text</title>The pilot studies CCQM-P225a and b aimed at validating the performance of the <italic toggle=\"yes\">pVT</italic>−CO<sub>2</sub> manometric reference facility maintained at the BIPM as a reference for the planned ongoing comparisons BIPM.QM-K2a and b for CO<sub>2</sub> in air and nitrogen standards, respectively, over the range 350 μmol mol<sup>−1</sup> to 800 μmol mol<sup>−1</sup>. The planned launch date of the BIPM.QM-K2a and b comparisons is 2024 and will enable NMIs and DIs to have access to on-demand comparisons for their CO2 in air and nitrogen standards over the range 350 μmol mol<sup>−1</sup> to 800 μmol mol<sup>−1</sup>.The pilot studies supplemented the validation activities on the BIPM reference facility already reported in CCQM-P188, and ongoing validation studies against NIST, NOAA and VSL gas standards. A description of the BIPM facility performance will be submitted for publication in a peer-reviewed journal in 2023, with a full uncertainty analysis showing that it can operate with a standard uncertainty of 0.1 μmol mol<sup>−1</sup> over the amount fraction range of the comparison (Viallon et al 2023b).The comparison was organised using a sufficient number of independent standards, to demonstrate the performance of the BIPM system, whilst limiting the duration of the pilot study, allowing the key comparison to start as planned in 2024. Following discussions at the 44th GAWG meeting it was decided that comparisons with 3 independent standards at 3 nominal amount fraction values (380, 480 and 800 μmol mol<sup>−1</sup>) in the two matrices (air and nitrogen) would be sufficient.Results presented in this report show a good agreement between values assigned by participants and those measured at the BIPM, over the entire range of the comparison and for both matrices (air and nitrogen). The BIPM pVT−CO2 facility is ready to act as reference facility for the ongoing key comparison BIPM.QM−K2.To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/ccqm-p225\" 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 CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"20 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138680286","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}
Pub Date : 2023-11-23DOI: 10.1088/0026-1394/60/1a/06025
Siarhei Saroka, Gonzalo Walwyn Salas, Efimia Luchian, Ludwig Büermann, Alexandr Oborin, Simon Sukhishvili, Paula Toroi, Elmar Shahverdiyev, Andrey Orobinski, Nasir Mamyrbek
Main textThe 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 comparison reference value (CRV) was obtained as the mean result of the PTB and the VNIIM. Almost all participants obtained valid results which were consistent within the relative standard uncertainties of the comparison ranging from 0.28% to 2.6%. Some participants had unacceptable results.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 CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
{"title":"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)","authors":"Siarhei Saroka, Gonzalo Walwyn Salas, Efimia Luchian, Ludwig Büermann, Alexandr Oborin, Simon Sukhishvili, Paula Toroi, Elmar Shahverdiyev, Andrey Orobinski, Nasir Mamyrbek","doi":"10.1088/0026-1394/60/1a/06025","DOIUrl":"https://doi.org/10.1088/0026-1394/60/1a/06025","url":null,"abstract":"<title>Main text</title>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 comparison reference value (CRV) was obtained as the mean result of the PTB and the VNIIM. Almost all participants obtained valid results which were consistent within the relative standard uncertainties of the comparison ranging from 0.28% to 2.6%. Some participants had unacceptable results.To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/coomet-ri-i-s3\" 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 CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"8 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138680077","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}
Pub Date : 2023-11-16DOI: 10.1088/0026-1394/60/1a/08027
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 textSupplementary 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 CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
{"title":"Supplementary comparison SIM.QM-S9 - biogas","authors":"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","doi":"10.1088/0026-1394/60/1a/08027","DOIUrl":"https://doi.org/10.1088/0026-1394/60/1a/08027","url":null,"abstract":"<title>Main text</title>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 <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/sim-qm-s9\" 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 CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"28 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138689574","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}
Pub Date : 2023-11-16DOI: 10.1088/0026-1394/60/1a/06023
R Nylund, L A de Prez, P O Hetland, C E Andersen, P Aviles, C G Mulas, Z Msimang, L Czap, L Persson
Main textA 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 to respective BIPM key comparisons. The comparison results are published in the BIPM key comparison database (KCDB) under the reference EURAMET.RI(I)-K1.3 and EURAMET.RI(I)-K4.3. The comparison was made indirectly using three thimble-type ionization chambers as transfer instruments. The results are analyzed and presented in terms of degrees of equivalence suitable for entry in the BIPM key comparison database.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 CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
{"title":"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)","authors":"R Nylund, L A de Prez, P O Hetland, C E Andersen, P Aviles, C G Mulas, Z Msimang, L Czap, L Persson","doi":"10.1088/0026-1394/60/1a/06023","DOIUrl":"https://doi.org/10.1088/0026-1394/60/1a/06023","url":null,"abstract":"<title>Main text</title>A key comparison of the standards for air kerma and absorbed dose to water of seven participating laboratories was carried out in the <sup>60</sup>Co 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 to respective BIPM key comparisons. The comparison results are published in the BIPM key comparison database (KCDB) under the reference EURAMET.RI(I)-K1.3 and EURAMET.RI(I)-K4.3. The comparison was made indirectly using three thimble-type ionization chambers as transfer instruments. The results are analyzed and presented in terms of degrees of equivalence suitable for entry in the BIPM key comparison database.To reach the main text of this paper, click on <ext-link xlink:href=\"https://www.bipm.org/documents/d/guest/euramet-ri-i-k1-3_euramet-ri-i-k4-3\" 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 CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"14 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692858","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}
Pub Date : 2023-11-14DOI: 10.1088/1681-7575/ad0c9f
Stefaan Pommé, Heiko Stroh, Timotheos Altzitzoglou, Jan Paepen, Raf Van Ammel, Maria Marouli, Leen Verheyen, Michael Unterweger, Ryan Fitzgerald, Denis Bergeron, L Pibida, Ole J. Naehle, Karsten Kossert, Natasha Ramirez, Emma Bendall, Andrew Fenwick, Kelley Ferreira, John Keightley, Mihaela Baker, Sean Collins, Carine Michotte, Sammy Courte, Romain Maximilien Coulon, Tim Jackson, Freda Van Wyngaardt, Aldo Fazio, Pierino De Felice, Branko Vodenik, M Korun, Frederic Juget, Claude J Bailat, Youcef Nedjadi, Francois O Bochud, Thierry Buchillier, Timothy Roy, Raphael Galea, Ivan Kajan, Milton van Rooy, Paul McGinnity, Ivana Tucakovic, Iolanda Osvath, Krzysztof Pelczar
Abstract 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 correlated with the observed instabilities in these radioactivity measurements. In fact, when compensating the residuals for a linear relationship with absolute humidity in air, most of the annual cycles are no longer statistically significant. As a result, the validity of the exponential-decay law can now be demonstrated with even higher fidelity.
{"title":"Ambient humidity, the overlooked influencer of radioactivity measurements","authors":"Stefaan Pommé, Heiko Stroh, Timotheos Altzitzoglou, Jan Paepen, Raf Van Ammel, Maria Marouli, Leen Verheyen, Michael Unterweger, Ryan Fitzgerald, Denis Bergeron, L Pibida, Ole J. Naehle, Karsten Kossert, Natasha Ramirez, Emma Bendall, Andrew Fenwick, Kelley Ferreira, John Keightley, Mihaela Baker, Sean Collins, Carine Michotte, Sammy Courte, Romain Maximilien Coulon, Tim Jackson, Freda Van Wyngaardt, Aldo Fazio, Pierino De Felice, Branko Vodenik, M Korun, Frederic Juget, Claude J Bailat, Youcef Nedjadi, Francois O Bochud, Thierry Buchillier, Timothy Roy, Raphael Galea, Ivan Kajan, Milton van Rooy, Paul McGinnity, Ivana Tucakovic, Iolanda Osvath, Krzysztof Pelczar","doi":"10.1088/1681-7575/ad0c9f","DOIUrl":"https://doi.org/10.1088/1681-7575/ad0c9f","url":null,"abstract":"Abstract 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 correlated with the observed instabilities in these radioactivity measurements. In fact, when compensating the residuals for a linear relationship with absolute humidity in air, most of the annual cycles are no longer statistically significant. As a result, the validity of the exponential-decay law can now be demonstrated with even higher fidelity.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"20 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134953765","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}
Pub Date : 2023-11-14DOI: 10.1088/1681-7575/ad0c9e
Kinza Maham, Vili Kosonen, Juha Peltoniemi, Petri Kärhä, Erkki Ikonen
Abstract 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 value 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 is inversely proportional to the order of the harmonic in all studied key comparisons. This new finding gives important information on the characteristics of spectral correlations. The result can be used in the uncertainty evaluation of spectral integrals, where the effect of unknown spectral correlations has earlier been challenging to assess quantitatively.
{"title":"Spectral analysis of deviations from key comparison reference values","authors":"Kinza Maham, Vili Kosonen, Juha Peltoniemi, Petri Kärhä, Erkki Ikonen","doi":"10.1088/1681-7575/ad0c9e","DOIUrl":"https://doi.org/10.1088/1681-7575/ad0c9e","url":null,"abstract":"Abstract 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 value 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 is inversely proportional to the order of the harmonic in all studied key comparisons. This new finding gives important information on the characteristics of spectral correlations. The result can be used in the uncertainty evaluation of spectral integrals, where the effect of unknown spectral correlations has earlier been challenging to assess quantitatively.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"17 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134953580","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}
Pub Date : 2023-11-13DOI: 10.1088/1681-7575/ad023e
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
Abstract 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 time. The fractional combined type B uncertainty is evaluated at 4.3 × 10 −16 . A frequency comparison has been conducted between NTSC-CsF2 and the SI second through a Global Navigation Satellite System link for eight months whose results show a fractional frequency difference of 4.2(5.2) × 10 −16 . With a reduced chi-square of 0.8, NTSC-CsF2 is found to be consistent with that of the other fountains within the uncertainty.
{"title":"First evaluation of the Primary Frequency Standard NTSC-CsF2","authors":"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","doi":"10.1088/1681-7575/ad023e","DOIUrl":"https://doi.org/10.1088/1681-7575/ad023e","url":null,"abstract":"Abstract 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 time. The fractional combined type B uncertainty is evaluated at 4.3 × 10 −16 . A frequency comparison has been conducted between NTSC-CsF2 and the SI second through a Global Navigation Satellite System link for eight months whose results show a fractional frequency difference of 4.2(5.2) × 10 −16 . With a reduced chi-square of 0.8, NTSC-CsF2 is found to be consistent with that of the other fountains within the uncertainty.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"7 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134992703","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}
Pub Date : 2023-11-10DOI: 10.1088/1681-7575/ad088b
Thomas Parker, Roger Brown, Jeffrey Sherman
Abstract 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, TIE RMS , provides the RMS time dispersion. The time deviation statistic (TDEV) or a variation on the Allan deviation (ADEV), referred to here as ADEVS, provide information on the nature of the random fluctuations in aging. This paper describes analytical and Monte Carlo techniques used to estimate the aging (time dispersion) from TDEV or ADEVS statistics, and finds that the aging can be more than a factor of four larger than TDEV or ADEVS. The use of ADEVS is recommended over TDEV since it is sensitive to time drift.
{"title":"Statistics for quantifying aging in time transfer system delays","authors":"Thomas Parker, Roger Brown, Jeffrey Sherman","doi":"10.1088/1681-7575/ad088b","DOIUrl":"https://doi.org/10.1088/1681-7575/ad088b","url":null,"abstract":"Abstract 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, TIE RMS , provides the RMS time dispersion. The time deviation statistic (TDEV) or a variation on the Allan deviation (ADEV), referred to here as ADEVS, provide information on the nature of the random fluctuations in aging. This paper describes analytical and Monte Carlo techniques used to estimate the aging (time dispersion) from TDEV or ADEVS statistics, and finds that the aging can be more than a factor of four larger than TDEV or ADEVS. The use of ADEVS is recommended over TDEV since it is sensitive to time drift.","PeriodicalId":18444,"journal":{"name":"Metrologia","volume":"66 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135087364","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}
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