Comité Consultatif de Thermométrie

Comité Consultatif de Thermométrie The Comité Consultatif de Thermométrie is an advisory committee within the Bureau International des Poids et Mesures focused on thermometry, metrology of temperature, and the international realization of the kelvin. It has provided technical guidance on temperature scales, instrumentation, and fixed points, interacting with national metrology institutes such as the National Institute of Standards and Technology, Physikalisch-Technische Bundesanstalt, and National Physical Laboratory (United Kingdom). The committee links research outputs from universities, industrial laboratories, and international bodies like the International Organization for Standardization, International Bureau of Weights and Measures, and the International Committee for Weights and Measures.

History

The committee was established in the interwar period as part of reforms at the International Bureau of Weights and Measures that followed scientific debates involving figures affiliated with the Royal Society, Académie des sciences (France), and laboratories in Paris, London, and Berlin. Early work built on practical temperature studies by investigators associated with the Cavendish Laboratory, Physikalisch-Technische Reichsanstalt, and the National Physical Laboratory (United Kingdom), and drew on fixed-point research by scientists linked to the Metropolitan-Vickers and Royal Institution. Post-World War II expansion saw collaboration with metrology leaders at the National Bureau of Standards, Institut national de chimie physique, and the International Electrotechnical Commission, reflecting technological advances from groups at Massachusetts Institute of Technology, École Normale Supérieure, and ETH Zurich. Cold War era interactions included dialogue with the All-Union Scientific Research Institute and metrologists from the Czech Metrology Institute, while late 20th-century shifts followed contributions from CERN, National Research Council (Canada), and the Council of the European Union on harmonizing temperature measurement. Recent history features work tied to redefinitions of SI units debated at meetings of the General Conference on Weights and Measures, conferences hosted by the International Union of Pure and Applied Physics, and reports influenced by research at NIST, PTB, and BNM-LNE.

Organization and Membership

The committee operates under the auspices of the International Committee for Weights and Measures and coordinates with the General Conference on Weights and Measures. Membership comprises delegates from national metrology institutes including NIST, PTB, NPL, INRIM, CENAM, VNIIM, and KRISS, as well as representatives from professional learned societies such as the Institute of Physics, American Physical Society, Société Française de Physique, and Deutsche Physikalische Gesellschaft. Technical working groups have included scientists from University of Cambridge, Sorbonne University, Imperial College London, École Polytechnique, University of Tokyo, and Tsinghua University. Observers and liaisons have come from standards bodies like the International Organization for Standardization, International Electrotechnical Commission, European Committee for Standardization, and regional metrology organizations such as EURAMET and APMP.

Functions and Activities

The committee advises on realization of the kelvin, development of thermometric fixed points, and dissemination of temperature scales by coordinating intercomparisons, key comparisons, and technical protocols involving laboratories such as LNE, CEM, CSIR, and INMETRO. It organizes international comparisons under the framework of the Mutual Recognition Arrangement administered by the International Committee for Weights and Measures and supports measurement campaigns utilizing standards developed at NPL, PTB, and NIST. Activities include drafting recommendations for the General Conference on Weights and Measures, convening workshops with stakeholders from Siemens, ABB, Schneider Electric, and academia, and promoting traceability chains referenced to practical fixed points like those established in cryogenics work at CERN and low-temperature facilities at JILA.

Standards and Publications

The committee issues technical reports, guidance documents, and draft protocols that inform standards produced by ISO, IEC, and regional bodies such as DIN and AFNOR. Key deliverables have addressed realization of the International Temperature Scale, intercomparison procedures, uncertainty evaluation following principles from the Guide to the Expression of Uncertainty in Measurement, and calibration methods used in industries represented by ASTM International and IEEE. Publications often cite measurement research from NPL, PTB, NIST, BNM-LNE, and academic studies at MIT, Caltech, and University of Oxford. Its reports underpin international standards on sensors, blackbody radiation sources, fixed-point cells, and noise-limited thermometry applied in sectors led by Airbus, Boeing, GE, and Siemens.

International Role and Collaborations

The committee plays a central role in global coordination of temperature metrology through partnerships with the General Conference on Weights and Measures, International Organization for Standardization, International Electrotechnical Commission, and regional metrology organizations including EURAMET, APMP, SIM, and CIPM MRA signatories. Collaborative projects have linked laboratories from United States, Germany, United Kingdom, France, Italy, Japan, China, Canada, Russia, and Brazil to harmonize temperature scales and participate in key comparisons administered by the BIPM. Joint initiatives involve research centers such as PTB, NIST, and NPL and cross-disciplinary collaborations with physics institutes including Max Planck Institute for Physics, CNRS, and RIKEN to advance optical thermometry, Johnson noise thermometry, and dynamic temperature measurement techniques used in metrology and industry.

Category:Metrology