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TitleUncertainty budgets for calibration of radiation thermometers below the silver point
Publication TypeJournal Article
Year of Publication2008
AuthorsSaunders, P., Fischer J., Sadli M., Battuello M., Park C.W., Yuan Z., Yoon H., Li W., Van Der Ham E., Sakuma F., Ishii J., Ballico M., MacHin G., Fox N., Hollandt J., Matveyev M., Bloembergen P., and Ugur S.
JournalInternational Journal of Thermophysics
Pagination1066 - 1083
Date Published2008
ISSN0195928X (ISSN)
KeywordsFreezing, Freezing point, Measurement theory, Radiation thermometry, Silver, Spectral responsivity, Thermometers, Uncertainty analysis, Wavelength
AbstractBelow the freezing point of silver, radiation thermometers are generally calibrated by implementing the multi-point interpolation method using blackbody measurements at three or more calibration points, rather than the ITS-90 extrapolation technique. The interpolation method eliminates the need to measure the spectral responsivity and provides greater accuracy at the longer wavelengths required below the silver point. This article identifies all the sources of uncertainty associated with the interpolation method, in particular, those related to the reference blackbody temperatures (either variable-temperature or fixed-point blackbodies) and to the measured thermometer signals at these points. Estimates are given of the 'normal' and 'best' uncertainties currently achievable. A model of the thermometer response is used to propagate all the uncertainties at the reference points and provide a total uncertainty at any temperature within the calibration range. The multi-point method has the effect of constraining the total uncertainty over this range, unlike the ITS-90 technique for which the uncertainties propagate as T 2. This article is a joint effort of the working group on radiation thermometry of the Consultative Committee for Thermometry (CCT), summarizing the knowledge and experience of all experts in this field. © 2008 Springer Science+Business Media, LLC.

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