Skip to main content
SpringerLink
Log in

The Discontinuity in the First Derivative of the ITS-90 at the Triple Point of Water

  • Published:
International Journal of Thermophysics Aims and scope Submit manuscript

Abstract

This paper investigates the discontinuity in the derivative [dW/dT 90]TPW of the ITS-90 at the triple point of water, using data for over 40 calibrated standard platinum resistance thermometers (SPRTs). It finds that the discontinuity is in most cases somewhere between 0 and −6 parts in 105, in relative terms, but that the higher numerical values are obtained for ‘less ideal’ SPRTs (those with lower temperature coefficients of resistance), and also for sub-ranges not extending beyond the indium point. These results are investigated vis-à-vis the long-standing observation that the ITS-90 reference values W r(Ga) and W r(Hg) are not completely consistent with data for W(Ga) and W(Hg) for real SPRTs. It discusses what may be done in a future scale to ensure continuity in the first derivative, and it concludes with a comment about the acceptance criteria for SPRTs in the scale.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Kemp R.C.: Metrologia 28, 327 (1991)

    Article  ADS  Google Scholar 

  2. Crovini L., Jung H.J., Kemp R.C., Ling S.K., Mangum B.W., Sakurai H.: Metrologia 28, 317 (1991)

    Article  ADS  Google Scholar 

  3. Supplementary Information for the ITS-90, BIPM (1990) http://www.bipm.org/en/publications/its-90_supplementary.html

  4. Meyer C.W., Tew W.L.: Metrologia 43, 341 (2006)

    Article  ADS  Google Scholar 

  5. R.L. Rusby, in The Mercury Point in the ITS-90. CCT/93-29, BIPM (1993)

  6. Singh Y.P., Maas H., Edler F., Zaidi Z.H.: Metrologia 31, 49 (1994)

    Article  ADS  Google Scholar 

  7. Hill K.D.: Metrologia 32, 87 (1995)

    Article  ADS  Google Scholar 

  8. Pitre L., Moldover M.R., Tew W.L.: Metrologia 43, 142 (2006)

    Article  ADS  Google Scholar 

  9. J. Fischer, M. de Podesta, K.D. Hill, M. Moldover, L. Pitre, R. Rusby, P. Steur, O. Tamura, R. White, L. Wolber, Int. J. Thermophys. (submitted)

  10. White D.R., Strouse G.F.: Metrologia 46, 101 (2009)

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Engineering Measurements Division, National Physical Laboratory, Teddington, TW11 0LW, UK

    R. L. Rusby

Authors
  1. R. L. Rusby
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to R. L. Rusby.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Rusby, R.L. The Discontinuity in the First Derivative of the ITS-90 at the Triple Point of Water. Int J Thermophys 31, 1567–1572 (2010). https://doi.org/10.1007/s10765-010-0794-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10765-010-0794-9

Keywords

Search

Navigation