Measurement Techniques

, Volume 48, Issue 9, pp 883–893

Analysis of Key Comparison Data: Unstable Travelling Standards

  • C. Elster
  • W. Woger
  • M. Cox
Article

Abstract

A procedure for the analysis of key comparison data is proposed in the case where the travelling standard shows a deterministic or random drift. It is assumed that some parametric model such as a linear trend is appropriate for modelling the deterministic part of the drift. The random part of the drift is assumed to be adequately described by a random walk model. The chosen drift model is determined by least squares and a model check is carried out. If the model check is satisfied, the derived drift model is applied to determine degrees of equivalence. A star-type sequence is required for the comparison in order to check the adequacy of the random drift model. The procedure is illustrated by its application to simulated data.

Key words

key comparison stability random walk least squares 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

REFERENCES

  1. 1.
    “Mutual recognition of national measurement standards and of calibration and measurement certificates issued by national metrology institutes,” in: Technical Report, International Committee for Weights and Measures (1999).Google Scholar
  2. 2.
    Guide to the Expression of Uncertainty in Measurement, 2nd ed., Geneva, International Organization for Standardization (1995).Google Scholar
  3. 3.
    M. G. Cox, “The evaluation of key comparison data,” Metrolog., 39, 589–595 (2002).Google Scholar
  4. 4.
    M. Desenfant, “Drift problems with the circulated standard during comparisons,” in: Proceedings of the International Workshop on Data Analysis of Key Comparisons, D. Richter, W. Woger, and W. Haesselbarth (eds.), PTB Bericht IT-10, 55–62 (2003).Google Scholar
  5. 5.
    L. Nielsen, “Evaluation of the calibration history of a measurement standard,” in: Proceedings of the International Workshop on Data Analysis of Key Comparisons, D. Richter, W. Woger, and W. Haesselbarth (eds.), PTB Bericht IT-10, 135–140 (2003).Google Scholar
  6. 6.
    R. B. Frenkel, “Comparison of artefact standards by more than two laboratories,” Metrolog., 39, 21–29 (2002).Google Scholar
  7. 7.
    K. Weise and W. Woger, “Removing model and data nonconformity in measurement evaluation,” Meas. Sci. Technol., 11, 1649–1658 (2000).CrossRefADSGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • C. Elster
    • 1
  • W. Woger
    • 2
  • M. Cox
    • 3
  1. 1.Physikalisch-Technische Bundesanstalt BerlinBerlinGermany
  2. 2.Physikalisch-Technische Bundesanstalt BraunschweigBraunschweigGermany
  3. 3.National Physical LaboratoryTeddingtonUK

Personalised recommendations