The Development of a Practical, Drift-Free, Johnson-Noise Thermometer for Industrial Applications

  • Paul Bramley
  • David CruickshankEmail author
  • Jonathan Pearce
Part of the following topical collections:
  1. TEMPMEKO 2016: Selected Papers of the 13th International Symposium on Temperature, Humidity, Moisture and Thermal Measurements in Industry and Science


Johnson noise thermometers measure a phenomenon that is directly linked to thermodynamic temperature by a fundamental physical law. The measurement of Johnson noise therefore offers the prospect of realizing a drift-free thermometer. Despite previous attempts to produce a practical Johnson noise thermometer for industrial applications, the technique is currently used only in niche research applications to explore discrepancies between practical temperature scales and thermodynamic temperature, or to determine Boltzmann’s constant. This has largely been due to the historical use of switched correlators to measure Johnson noise, which limits the sense resistance and measurement bandwidth that can be employed. This constraint limits the Johnson noise signal to levels near the limits of measurement. A new technique that eliminates switching and thereby allows the use of much higher sense resistances and bandwidths to increase the Johnson noise signal is presented. The signal power achieved is significantly higher than for systems using a switched correlator. Results so far indicate that measurement performance is compatible with the requirements of industrial applications. Specifically, uncertainties of \({<}0.3 \, {^{\circ }}\hbox {C}\) (95 % confidence) were demonstrated for measurements near ambient temperature with a measurement time of only 7 s.


Drift-free Johnson noise Thermometer 


  1. 1.
    S.W. Nam et al., Johnson noise thermometry measurements using a quantized voltage noise source for calibration. IEEE Trans. Instrum. Meas. 52, 550–554 (2003)CrossRefGoogle Scholar
  2. 2.
    D.R. White et al., The status of Johnson noise thermometry. Metrologia 33, 325–335 (1996)ADSCrossRefGoogle Scholar
  3. 3.
    M. de Podesta, Rethinking the kelvin. Nat. Phys. 12, 104 (2016)CrossRefGoogle Scholar
  4. 4.
    R.A. Kisner et al., Development of a Johnson Noise Thermometer for Nuclear Power Use. International Nuclear Energy Research Initiative, Final project report (2005)Google Scholar
  5. 5.
    J.B. Johnson, Thermal agitation of electricity in conductors. Nature 119, 50–51 (1927)ADSCrossRefGoogle Scholar
  6. 6.
    H. Nyquist, Thermal agitation of electric charge in conductors. Phys. Rev. 32, 110–113 (1928)ADSCrossRefGoogle Scholar
  7. 7.
    S.O. Rice, Mathematical analysis of random noise. Bell Syst. Tech. J. 23, 282–332 (1944)MathSciNetCrossRefGoogle Scholar
  8. 8.
    S.O. Rice, Mathematical analysis of random noise. Bell Syst. Tech. J. 24, 46–156 (1945)MathSciNetCrossRefGoogle Scholar
  9. 9.
    D.R. White et al., Measurement time and statistics for a noise thermometer with a synthetic-noise reference. Metrologia 45, 395 (2008)ADSCrossRefGoogle Scholar
  10. 10.
    D.R. White, S.P. Benz, Constraints on a synthetic-noise source for Johnson noise thermometry. Metrologia 45, 93–101 (2008)ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Paul Bramley
    • 1
  • David Cruickshank
    • 1
    Email author
  • Jonathan Pearce
    • 2
  1. 1.Metrosol LimitedPlum Park EstatePaulerspury, NorthamptonshireUK
  2. 2.National Physical LaboratoryTeddington, MiddlesexUK

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