No graphs of equivalence are included in the KCDB for this comparison.
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for November 2023
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for December 2023
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for January 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for February 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for March 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for April 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for May 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for June 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for July 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for August 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for September 2024
Degrees of equivalence Dk = [UTC - UTC (k)] and associated expanded uncertainty Uk for October 2024
| Metrology area, Sub-field | Time and Frequency, Time |
| Description | Calculation of the reference time scale UTC (Coordinated Universal Time) |
| Time of measurements | 1977 - |
| Status | Continuous, approved for equivalence |
| References |
Guidelines for participation in the ongoing key comparison in time CCTF-K001.UTC |
| Measurand | [UTC - UTC(k)] in ns UTC(k) is the local representation of UTC maintained by the laboratory k |
| Transfer device | Time transfer between participants is carried out using Global Positioning System (GPS) and Two-Way Satellite Time and Frequency Transfer (TWSTFT) |
| Comparison type | Key Comparison |
| Consultative Committee | CCTF (Consultative Committee for Time and Frequency) |
| Conducted by | CCTF (Consultative Committee for Time and Frequency) |
| Comments | Most recent KCDB update: 15 November 2024 Values are available every 5 days on MJD's ending by "4" and "9" (MJD: Modified Julian Day). They are published in the monthly Circular T and in the BIPM Time Section Annual Report. The laboratories listed in the tab "Participants" are those which contributed to the Circular T. The RMO indicated is the RMO representing the National Metrology Institute of the state or economy. At its 17th meeting in September 2006, the CCTF decided to assign the identifier "CCTF-K001.UTC" to this key comparison, first registered as "CCTF-K2001.UTC" in January 2005 (see page 28 of the Report of the 17th CCTF meeting). This was implemented in the KCDB on 19 March 2007. Additonal data for CCTF-K001.UTC: https://www.bipm.org/en/time-metrology gives access to successive issues of Circular T since No 125 (May 1998), and complete sets of values of [UTC - UTC(k)] since 1998. |
| Pilot institute |
BIPM
Bureau International des Poids et Mesures BIPM - International Organization |
| Contact person | Patrizia Tavella +33 (0)1 45 07 70 76 |
| Pilot laboratory | |
|---|---|
| BIPM |
Bureau International des Poids et Mesures, BIPM - International Organization, N/A |
| AOS |
Astrogeodynamical Observatory, Space Research Centre P.A.S., Poland, EURAMET |
| APL |
Applied Physics Laboratory, United States, SIM |
| BEV |
Bundesamt für Eich- und Vermessungswesen, Austria, EURAMET |
| BFKH |
Government Office of the Capital City Budapest, Hungary, EURAMET |
| BIM |
Bulgarian Institute of Metrology, Bulgaria, EURAMET |
| BIRM |
Beijing Institute of Radio Metrology and Measurement, China, APMP |
| BMM |
Bureau of Metrology (Montenegro), Montenegro, EURAMET |
| Note: |
| BOM |
Bureau of Metrology, Ministry of Economy (North Macedonia), North Macedonia, EURAMET |
| BSJ |
Bureau of Standards Jamaica, Jamaica, SIM |
| BelGIM |
Belarussian State Institute for Metrology, Belarus, COOMET |
| Note: |
| CAO |
Cagliari Astronomical Observatory, Italy, EURAMET |
| CENAM |
Centro Nacional de Metrologia, Mexico, SIM |
| Note: |
| CENAMEP AIP |
Centro Nacional de Metrología de Panama AIP, Panama, SIM |
| Note: |
| CNES |
Centre National d'Études Spatiales, France, EURAMET |
| DEF-NAT |
Laboratoire de Métrologie de la Direction Générale des Transmissions et de l'Informatique, Tunisia, AFRIMETS |
| Note: |
| DFM |
Danish Fundamental Metrology A/S, Denmark, EURAMET |
| DLR |
Deutsche Zentrum fuer Luft - und Raumfahrt (German Aerospace Center), Germany, EURAMET |
| DMDM |
Directorate of Measures and Precious Metals, Serbia, EURAMET |
| DTAG |
Deutsche Telekom AG, Germany, EURAMET |
| DZM |
State Office for Metrology, Croatia, EURAMET |
| Note : |
registered under the acronym "IFZG" in Circular T |
| EIM |
Hellenic Institute of Metrology, Greece, EURAMET |
| EMI |
Emirates Metrology Institute, United Arab Emirates, GULFMET |
| Note: |
| ESA |
European Space Agency - European Space Research and Technology Centre, European Union, EURAMET |
| FTMC |
Center for Physical Sciences and Technology, Lithuania, EURAMET |
| Note |
| GUM |
Glowny Urzad Miar, Central Office of Measures, Poland, EURAMET |
| Note: |
| HKO |
Hong Kong Observatory, Hong Kong, China, APMP |
| IFAG |
Bundesamt für Kartographie und Geodäsie, Germany, EURAMET |
| IGNA |
Instituto Geográfico Nacional, Argentina, SIM |
| ILNAS |
Bureau Luxembourgeois de Métrologie, Luxembourg, EURAMET |
| IMBIH |
Institute of Metrology of Bosnia and Herzegovina, Bosnia and Herzegovina, EURAMET |
| Note: |
| INACAL |
National Institute for Quality, Peru, SIM |
| Note: |
| INM |
National Institute of Metrology, Romania, EURAMET |
| Note: |
| INM (CO) |
Instituto Nacional de Metrología de Colombia, Colombia, SIM |
| Note: |
| INMETRO |
Instituto Nacional de Metrologia, Qualidade e Tecnologia, Brazil, SIM |
| Note: |
| INPL |
National Physical Laboratory of Israel, Israel, N/A |
| INRIM |
Istituto Nazionale di Ricerca Metrologica, Italy, EURAMET |
| Note: |
| INTI |
Instituto Nacional de Tecnologia Industrial, Argentina, SIM |
| IPE/ASCR |
Institute of Photonics and Electronics, Czech Academy of Sciences, Czechia, EURAMET |
| Note: |
| IPQ |
Instituto Portugues da Qualidade, Portugal, EURAMET |
| JATC |
Joint Atomic Time Commission, China, APMP |
| JV |
Justervesenet, Norway, EURAMET |
| KEBS |
Kenya Bureau of Standards, Kenya, AFRIMETS |
| KRISS |
Korea Research Institute of Standards and Science, Korea, Republic of, APMP |
| Note: |
| KazStandard |
Kazakhstan Institute of Standardization and Metrology, Kazakhstan, COOMET |
| Note: |
| LACOMET |
Laboratorio Costarricense de Metrologia, Costa Rica, SIM |
| Note: |
| LNE-SYRTE |
Observatoire de Paris/Systèmes de Référence Temps-Espace, France, EURAMET |
| Note: |
| LRTE |
Laboratorio de Referencia de Tempo e Espaço, Brazil, SIM |
| MASM |
Mongolian Agency for Standardization and Metrology, Mongolia, APMP |
| METAS |
Federal Institute of Metrology, Switzerland, EURAMET |
| Note: |
| MIKES |
VTT Technical Research Centre of Finland Ltd, Centre for Metrology/Mittatekniikan keskus, Finland, EURAMET |
| Note: |
| MIRS/SIQ/Metrology |
MIRS/Slovenian Institute of Quality and Metrology/Metrology, Slovenia, EURAMET |
| Note |
| MSL |
Measurement Standards Laboratory, New Zealand, APMP |
| MTC |
MAKKAH Time Centre - King Abdulah Centre for Crescent Observations and Astronomy, Saudi Arabia, GULFMET |
| MUSSD |
Department of Measurement Units, Standards and Services, Sri Lanka, APMP |
| Note: |
registered under the acronym “SL” in Circular T |
| NAO |
National Astronomical Observatory, Japan, APMP |
| NICT |
National Institute of Information and Communications Technology, Japan, APMP |
| NIM |
National Institute of Metrology, China, APMP |
| NIMT |
National Institute of Metrology (Thailand), Thailand, APMP |
| NIS |
National Institute for Standards, Egypt, AFRIMETS |
| NIST |
National Institute of Standards and Technology, United States, SIM |
| NMC, A*STAR |
National Metrology Centre, Agency for Science, Technology and Research, Singapore, APMP |
| Note: |
| NMIA |
National Measurement Institute, Australia, Australia, APMP |
| Note: |
| NMIJ AIST |
National Metrology Institute of Japan, Japan, APMP |
| NMIM |
National Metrology Institute of Malaysia, Malaysia, APMP |
| Note: |
| NMISA |
National Metrology Institute of South Africa, South Africa, AFRIMETS |
| Note: |
| NPL |
National Physical Laboratory, United Kingdom, EURAMET |
| NPLI |
CSIR National Physical Laboratory of India, India, APMP |
| NRC |
National Research Council, Canada, SIM |
| NRL |
US Naval Research Laboratory, United States, SIM |
| NSAI NML |
NSAI National Metrology Laboratory, Ireland, EURAMET |
| NSC IM |
National Scientific Centre "Institute of Metrology", Ukraine, EURAMET |
| Note: |
| NTSC |
National Time Service Center of China, China, APMP |
| ON/DSHO |
Observatório Nacional/Serviço Nacional da Hora, Brazil, SIM |
| Note: |
| ONBA |
Observatorio Naval Buenos Aires, Argentina, SIM |
| ORB |
Observatoire Royal de Belgique, Belgium, EURAMET |
| PTB |
Physikalisch-Technische Bundesanstalt, Germany, EURAMET |
| RISE |
Research Institutes of Sweden AB, Sweden, EURAMET |
| Note: |
| ROA |
Real Instituto y Observatorio de la Armada, Spain, EURAMET |
| SASO-NMCC |
National Measurement and Calibration Center - Saudi Standards, Metrology and Quality Organization, Saudi Arabia, GULFMET |
| Note: |
registered under the acronym “SASO” in Circular T |
| SCL |
Standards and Calibration Laboratory, Hong Kong, China, APMP |
| SMD |
Service de la Métrologie Belge, Belgium, EURAMET |
| SMU |
Slovensky Metrologicky Ustav, Slovakia, EURAMET |
| SNSU-BSN |
National Measurement Standard - National Standardization Agency of Indonesia, Indonesia, APMP |
| Note: |
registered under the acronym "IDN" in Circular T |
| TL |
Telecommunication Laboratories, ChungHwa Telecom Co. Ltd., Chinese Taipei, APMP |
| UME |
TÜBITAK Ulusal Metroloji Enstitüsü, Türkiye, EURAMET |
| USNO |
United States Naval Observatory, United States, SIM |
| UzNIM |
Uzbek National Institute of Metrology, Uzbekistan, COOMET |
| VMI-STAMEQ |
Viet Nam Metrology Institute, Directorate for Standards and Quality, Viet Nam, APMP |
| Note: |
| VNIIFTRI |
Institute of Physical Technical and Radiotechnical Measurements, Rosstandart, Russian Federation, COOMET |
| Note: |
| VSL |
VSL, Netherlands, EURAMET |
This page proposes print-out on A4 paper (portrait) of the comparison details (best printed out using a black and white printer).
Please, select items to be printed out, then click on "OK" :
The key comparison reference value of the key comparison CCTF-K001.UTC is UTC, as decided by the CCTF at its 15th meeting held in 2001.The degree of equivalence of each laboratory k with respect to the key comparison reference value is given by a pair of terms both expressed in ns:
Dk = [UTC - UTC (k)], where UTC (k) is the local representation of UTC maintained by laboratory k, and Uk, the expanded uncertainty (coverage factor equal to 2), of Dk.
The KCDB gives access to the degrees of equivalence for the last 12 months.
Uk = 2uk where uk is the combined standard uncertainty of [UTC - UTC (k)].
Uk does not include the prediction component due to the delay of publication of [UTC ‑ UTC (k)].
The uk values are valid for the whole month of calculation.
No Laboratory Individual Measurements are available from the KCDB for this comparison.
