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TitleA theory of reflections for traceable radiation thermometry
Publication TypeJournal Article
Year of Publication1995
AuthorsSaunders, P., and White D.R.
Pagination1 - 10
Date Published1995
ISSN00261394 (ISSN)
AbstractThis paper develops a model that provides the means to calculate the errors and uncertainties in radiation thermometry measurements affected by reflections. This addresses the serious and frequently encountered problem of ensuring traceability when measuring the temperature of non-black objects. Measurement strategies are outlined for the three situations where there exists an extraneous source of radiation at a much lower, similar, and much higher temperature than that of the object of interest. In the first strategy shorter-wavelength thermometers have smaller reflection errors and experimental uncertainties than longer-wavelength thermometers. In the second strategy there is an optimum operating wavelength that makes a compromise between the reflection error and the uncertainty. In the third strategy, which corrects for the reflection error, there is also an optimum wavelength for which the uncertainty attains a minimum value. By considering all of the practical factors involved, this approach reveals limitations in previous error analyses which concluded that the longest-wavelength thermometers should be used to minimize reflection errors. Recommendations are given for the use of the three strategies in minimizing reflection errors and uncertainties.

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