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TitleOn the thermodynamic accuracy of the ITS-90: Platinum resistance thermometry below 273 K
Publication TypeJournal Article
Year of Publication1995
AuthorsNicholas, J.V.
Pagination71 - 77
Date Published1995
ISSN00261394 (ISSN)
AbstractAn analysis of the resistance-temperature relationship for six low-temperature platinum resistance thermometers is carried out to determine the thermodynamic accuracy of the ITS-90 below 273 K. The use of smooth thermodynamic functions in a model equation for platinum resistance indicates that there is a significant deviation of the ITS-90 from thermodynamic values over the range 80 K to 270 K. The deviation is consistent with recent results in acoustic and gas thermometry, namely around 10 mK at 150 K. For this reason a re-evaluation of the existing thermodynamic data on the temperature scale appears warranted.

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