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NPL at the Royal Institution of Great Britain

Graham Machin

Graham Machin

NPL Senior Fellow

Professor Graham Machin, FREng, BSc (Hons), DPhil (Oxon), DSc, FInstP, FInstMC, FIPEM, CEng, CPhys is a Senior NPL Fellow in Thermometry. His team made world-leading contributions to the redefinition of the kelvin (K), thermodynamic temperature measurement and the development of high temperature fixed points as next-generation temperature standards. In addition, his team have made numerous contributions to solving thermometry problems in harsh environments as diverse as aerospace, space, nuclear decommissioning and medical, and is working towards developing traceable surface thermometry, in-situ validation, and no-drift sensing thermometry techniques to facilitate autonomous production/Industry 4.0. Graham is also the NPL science lead for nuclear decommissioning metrology.

Areas of interest

As an acknowledged world leader in thermometry, Graham and his team have made significant contributions to the science of temperature measurement. Recent highlights include:

  • One of the world’s lowest uncertainty evaluations of the Boltzmann constant for the kelvin redefinition
  • The world’s lowest uncertainty primary thermometry measurements below 303 K
  • Establishment of high temperature fixed points as the next generation temperature standards (for non-contact and thermocouple thermometry) and for the in-situ validation of temperature sensors
  • Novel traceable surface thermometry techniques for a wide range of harsh environments
  • First traceable thermometry for flames and quantitative thermal imaging in a range of environments
  • Development of photonic and, building on the kelvin redefinition, practical primary thermometry
  • Reliable thermometry in a range of health care settings including triaging fever

Present activities include:

  • Leading international efforts for realising the redefined kelvin through the EMPIR Real-K and forthcoming EPM DireK-T (start Sep 2023) projects, and through chair of the CCT Working Group in Non-Contact Thermometry
  • Leading the development of reliable thermal (and other) based metrology tools for reliable decommissioning of nuclear facilities.
  • Founder member of the UK body temperature measurement group, whose aim is to reduce avoidable deaths, improve fever screening especially for pandemic preparedness and improve triaging throughout the health service
  • Leading the establishment of traceable photonic based thermometry approaches in the UK


Graham joined the NPL Temperature and humidity group in 1991, after completing his DPhil at the University of Oxford in “Cataclysmic variables in globular clusters and low mass X-ray binaries”. He has published over 250 papers and has given numerous plenary and keynote lectures around the world.

Graham is the NPL representative on the BIPM Consultative Committee for Thermometry (CCT), chair of the CCT working group (WG) for non-contact thermometry and a member both of the CCT WG on strategy and of the CCT TG for Digitalisation. He is a past chair of the EURAMET Technical Committee of Thermometry (TC-T) (2014–2018) and continues to serve on the TC-T Strategy Group. He has served on the EPSRC Physical Sciences Advisory Team (2014–2017), on the council of the Institute of Measurement and Control (InstMC) (2013–2015) and was its President (2018-2019). He has also served on numerous Conference International Programme Committees including the IMEKO World Congress 2018 and Tempmeko/Tempbejing 2019 and currently serves on the IPC of the decennial International Temperature Symposium (US, 2023). In 2020 he led the development of and chaired the inaugural session on nuclear decommissioning at the NPL virtual Conference on Applied Radiation Metrology. He holds visiting professorships in Physics at the Universities of Surrey and Strathclyde, honorary professorship at the University of Birmingham and is 'Colaborador Honorifico' at the University of Valladolid. In 2012, he received the InstMC Callendar Medal for improvements in “the state of the art” in temperature measurement; and in 2015, a DSc from the University of Birmingham for 'Improvements in Temperature Measurement'. In 2017, Graham was awarded a Chinese Academy of Sciences (CAS) Fellowship and in 2019 he was elected Honorary Scientist of the CAS and Fellow of the Royal Academy of Engineering. In 2021 he was awarded the InstMC Sir Harold Hartley Medal for “outstanding contributions to the technology of measurement and control”. In 2022 his team was awarded the joint InstMC/WCSIM “Cornish award” for outstanding achievement in building of scientific instruments and was the joint winner of the NPL Impact from Science award for nuclear decommissioning metrology. He currently serves as an invited member of the Parliamentary and Scientific Committee.

Read about Graham's main area of Temperature and humidity research

Email Graham Machin

Selected recent publications

Machin, G., et alTowards realising the redefined kelvin”, Measurement, 201 111725 (2022) (open access)

Dedyulin, S., Ahmed, D., Machin G., “Emerging technologies in the field of thermometry”, Meas. Sci. & Technol. 33 092001 (26pp) (2022)

Machin, G., Brettle, D., Fleming, S., Nutbrown, R., Simpson, R., Stevens, R., Tooley, M., “Is current body temperature measurement practice fit-for-purpose?”, J. Med. Eng. Technol. (2021) (open access)

Machin, G., Simpson, R., Sutton, G., Bond, W., Heaps, E., Hayes, M., Korniliou, S., McMillian, J., Norman, J., Sposito, A., Panicker, V.,  Adamska, A., Alexander, A., Bernard, R., Clarke, S., Clifford, J., Gallagher, C., Jowsey, J. “Novel thermometry approaches to facilitate safe and effective monitoring of nuclear material containers”, Nuclear Engineering and Design, 371, 110939 (2021)

Machin, G., Simpson, R., McEvoy, H., Whittam, A., “NPL contributions to the standardisation and validation of contemporary medical thermometry methods", Physiol. Meas. 40 05TR01 (2019)

Tucker, D., Andreu, A., Elliott, C., Ford, T., Neagu, M., Machin, G., Pearce, J., “Integrated self-validating thermocouples: with a reference temperature up to 1329 °C”, Meas. Sci. Technol. 29 105002 (2018)

Machin, G., “The Kelvin redefined”, Meas. Sci. Technol. 29 022001 (11pp) (2018)

Fletcher, T., Whittam, A., Simpson, R., Machin, G., “Comparison of non-contact infrared skin thermometers, J. Med. Eng. Technol. 42 65-71 (2018)

Machin, G., Whittam, A., Ainarkar, S., Allen, J., Bevans, J., Edmonds, M., Kluwe, B., MacDonald, A., Petrova, N., Plassmann, P., Ring, F., Simpson, R. “A thermal imaging system for the prevention of diabetic foot ulceration”, Physiol. Meas. 38 420-430 (2017)

Machin, G., Anhalt, K., Battuello, M., Bourson, F., Dekker, P., Diril, A., Edler, F., Elliott, C., Girard, F., Greenen, A., Kňazovická, L., Lowe, D., Pavlásek, P., Pearce, J., Sadli, M., Strnad, R., Seifert, M., Vuelban E. M., “The research outcomes of the European Metrology Research Programme Project:  HiTeMS – High Temperature Measurement Solutions for Industry”, Measurement 78 p. 168–179 (2016)

Fellmuth, B., Fischer, J., Machin, G., Picard, S., Steur, P., Tamura, O., White, R., Yoon H., “The kelvin redefinition and its mise en pratique”, Phil. Trans R. Soc. A.  374: 20150037 (2016)

Sadli, M., Machin, G., Anhalt, K., Bourson, F., Briaudeau, S., del Campo, D., Diril, A.,  Lowe, D., Mantilla Amor, J. M., Martin, J.M., McEvoy, H., Ojanen, M., Pehlivan, O., Rougié, B., Salim S. G. R.., “Realisation and dissemination of thermodynamic temperatures above the silver point”, Phil. Trans R. Soc. A.  374: 20150043 (2016)

Anhalt, K., Machin, G., “Thermodynamic temperature by primary radiometry”, Phil. Trans R. Soc. A.  374: 20150041 (2016)

Machin, G., Engert, J., Gavioso, R., Sadli, M., Woolliams, E., “Summary of achievements of the EMRP project implementing the new kelvin (InK)”, Measurement 94 149-156 (2016) doi:10.1016/j.measurement.2016.07.069

de Podesta, M., Yang, I., Mark, D., Underwood, R., Sutton, G., Machin, G.,Correction of NPL-2013 estimate of the Boltzmann constant for argon isotopic composition and thermal conductivityMetrologia 52 S353–S363 (2015) doi:10.1088/0026-1394/52/5/S353

View publications on ResearchGate

ORCID ID: 0000-0002-8864-6951