Development and Evaluation of a Co–C Eutectic-Point Cell for Thermocouple Calibration
2015 (English)In: International journal of thermophysics, ISSN 0195-928X, E-ISSN 1572-9567, Vol. 36, no 8, p. 1888-1894Article in journal (Refereed) Published
Abstract [en]
The cobalt–carbon (Co–C) eutectic point at 1324∘C has in previous studies proved to be suitable as a reference for thermocouple calibration above 1100∘C. For types S, R, and B, it fills the gap between the copper point and the palladium point, and for Pt/Pd thermocouples, it extends the range from the copper point. This work describes the implementation of the Co–C reference point at the Technical Institute of Sweden (SP). A Co–C cell was developed and manufactured at SP in a collaboration project with the National Metrology Institute of Japan (NMIJ). The principle of the cell is a hybrid design with double walls, both for the outer crucible and the inner thermometer well, with graphite foil between the walls. To evaluate the performance of the developed cell (SP cell), a comparison between the SP cell and another cell, manufactured and provided from the National Physics Laboratory (NPL) in England, is performed using Pt/Pd thermocouples as transfer standards. The comparison showed very good agreement, with differences below 40 mK, using the same furnace and two different thermocouples. The expanded uncertainty (k=2) for the comparison was estimated to be 70 mK.
Place, publisher, year, edition, pages
2015. Vol. 36, no 8, p. 1888-1894
Keywords [en]
Cobalt–carbon, Co–C, Eutectic point, Thermocouple calibration
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-6819DOI: 10.1007/s10765-015-1853-zScopus ID: 2-s2.0-84940721589Local ID: 23614OAI: oai:DiVA.org:ri-6819DiVA, id: diva2:964659
2016-09-082016-09-082020-12-01Bibliographically approved