A new technique for direct traceability of contact thermometry Co-C eutectic cells to the ITS-90
- Laboratoire Commun de Métrologie LNE-Cnam, 61 rue du Landy 93210 La Plaine Saint Denis (France)
The eutectic Co-C melting point is a promising system to serve as a thermometric fixed-point in the temperature range above 1084.62 °C (copper freezing point). During the last decade, LNE-Cnam has developed and characterized some fixed-point devices, based on eutectic Co-C alloy, for applications to contact and radiation thermometry. Above 962 °C, the ITS-90 is realized by radiation thermometry by the extrapolation from a Ag, Au or Cu fixed point using the Planck law for radiation. So the only way for assigning a temperature in the scale to a Co-C cell (∼1324 °C) is by radiation thermometry. An indirect method is commonly used to assign a temperature to a high-temperature fixed point (HTFP) cell designed for contact thermometry is to fill a pyrometric cell with the same mixture as the contact thermometry cell. In this case, the temperature assigned to the pyrometric cell is attributed to the contact cell. This paper describes a direct method allowing the determination of the melting temperature realized by a 'contact thermometry' Co-C cell by comparison to a 'radiation thermometry' Co-C cell whose melting temperature was assigned in accordance to the scale by extrapolation from the Cu point. In addition, the same Co-C cell is studied with a standard Pt/Pd thermocouple.
- OSTI ID:
- 22218022
- Journal Information:
- AIP Conference Proceedings, Vol. 1552, Issue 1; Conference: 9. international temperature symposium, Los Angeles, CA (United States), 19-23 Mar 2012; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
CARBON
COBALT
COMPARATIVE EVALUATIONS
COPPER
EUTECTICS
EXTRAPOLATION
MELTING POINTS
MIXTURES
PLANCK LAW
PYROMETERS
TEMPERATURE DEPENDENCE
TEMPERATURE MEASUREMENT
THERMOCOUPLES
THERMOMETERS