National Physical Laboratory

Jonathan Pearce

Current interests

Jonathan Pearce
  • Developing contact thermometry methods (thermocouples and resistance thermometers) to underpin UK standards and traceability in temperature measurement
  • Analytical and numerical modelling of physical systems
  • Solving real-world measurement problems in industry, government and academia
  • Temperature measurement in harsh environments

Current industrially-oriented research includes development of new and improved temperature measurement techniques applied to a suite of high value manufacturing applications in aerospace, automotive, and government, in particular through coordinating an 18-partner European project to enhance process control through improved temperature measurement, called EMPRESS. Key developments include both conventional devices such as thermocouples for extreme environments, as well as novel , primary thermometers such as a practical Johnson noise thermometer being developed with commercial partners. SI-oriented research includes modelling of solidification of very pure metals, characterisation of self-heating of resistance thermometers, and combinatorial calibration techniques.


Jonathan Pearce is a principal research scientist leading the contact thermometry technical area of the NPL Temperature Group. He joined NPL in 2006 after completing his PhD at the University of Liverpool on the physics of superfluid helium. He has worked as a physicist in the USA, France, Japan, and the UK. He has published about 120 papers on low temperature physics, temperature metrology, and industrial measurement issues. Research highlights include the development of new thermocouples and high temperature fixed points for contact thermometry, and modelling of the effect of sub-ppm impurities on the solidification of high purity metals for application to primary fixed points used as temperature standards. Jonathan's main interests are developing fit-for-purpose measurement systems, developing numerical and analytical models of physical systems, and providing robust, practical contact thermometry solutions. He currently represents the UK on two CCT working groups, concerned with uncertainties and dissemination of the SI kelvin. He is a Fellow of the Institute of Physics.

Selected publications

  • Extra points for thermometry, J.V. Pearce, Nature Physics, Vol. 13, January, p 104 (2017)
  • Optimising Pt-Rh thermocouple wire composition to minimise composition change due to evaporation of oxides, J.V. Pearce, Johnson Matthey Technology Review, 60 (4) 238-242 (2016)
  • The development of a practical, drift-free, Johnson noise thermometer for industrial applications, P. Bramley, D. Cruickshank, J.V. Pearce, Int J Thermophys, 38, 25 (2017)
  • Liquidus Slopes for Impurities in ITS-90 Fixed Points, J.V. Pearce, J.A. Gisby, P.P.M. Steur, Metrologia, 53, 1101-1114 (2016)
  • A System for High-Temperature Homogeneity Scanning of Noble-Metal Thermocouples, E. Webster, R. Mason, A. Greenen, J. Pearce, Int J Thermophys, 36, 2922–2939 (2015)
  • A phase-field model of solidification of almost pure ITS-90 fixed points, M.J. Large and J.V. Pearce, Int J Thermophys, 35, 1109-1126 (2014)
  • Distribution coefficients of impurities in metals, J.V. Pearce, Int J Thermophys, 35 (3), 628-635 (2014)
  • Optimising the extrapolation to zero current in SPRT self-heating corrections, J.V. Pearce, R.L. Rusby, P.M. Harris, and L. Wright, Metrologia, 50, 345-353 (2013)
  • Self-validating Type C thermocouples using high temperature fixed points, J.V. Pearce, C.J. Elliott, G. Machin, O. Ongrai, 9th International Temperature Symposium, AIP Conf Proc, 1552, 595 (2013)
  • Optimising heat treatment of gas turbine blades with a Co-C eutectic fixed point, J.V. Pearce, G. Machin, T. Ford, and S. Wardle, Int J Thermophysics, 222, 29 (2008)

Contact details

Tel: 020 8943 6886

Last Updated: 7 Dec 2017
Created: 1 Mar 2012


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