Abstract
Noble-metal thermocouples are amongst the most widely used thermocouples for high-temperature process measurement and as references. Although they are less susceptible to inhomogeneity effects than the more-common base-metal thermocouples, inhomogeneity is still the major source of uncertainty. Currently, most estimates of the uncertainty due to inhomogeneity are based on thermocouple specifications or historical performance of similar thermocouples. It is not common for the inhomogeneity to be measured directly, in part because there is no accepted method for measuring the inhomogeneities, and in part because there is no conclusive evidence linking the magnitude of inhomogeneities determined at the scanning temperature to the effects of the same inhomogeneities at other temperatures. This paper describes an inhomogeneity scanner able to be fitted to sodium heat-pipe furnaces to operate between \(600 {\,{}^{\circ }}\hbox {C}\) and \(1000 {\,{}^{\circ }}\hbox {C}\). Comparison of scans made at \(100 {\,{}^{\circ }}\hbox {C}\) demonstrates the scalability of some types of inhomogeneity in Type S and R thermocouples. It is concluded that for Type R and S thermocouples, a robust uncertainty assessment can be obtained from a scan made at a single temperature.
Similar content being viewed by others
References
W.P. White, Phys. Rev. (Ser. I) 23, 449–474 (1906)
J.V. Pearce, Meas. Sci. Technol. 18, 3489–3495 (2007)
M. Ballico, F. Jahan, in Temperature, Its Measurement and Control in Science and Industry, Part 1, vol. 8, ed. by C.W. Meyer (AIP, New York, 2013), pp. 544–548
E.S. Webster, D.R. White, Metrologia 52, 130–144 (2015)
F. Jahan, M. Ballico, in Temperature, Its Measurement and Control in Science and Industry, Part 1, vol. 7, ed. by D.C. Ripple (AIP, New York, 2002), pp. 523–528
Y.G. Kim, C.H. Song, K.S. Gam, I. Yang, Meas. Sci. Technol. 20, 1–5 (2009)
E.H. McLaren, E.G. Murdock, The Properties of Pt/PtRh Thermocouples for Thermometry in the Range 0–\(1100 {\,{}^{\circ }}\text{ C }\), Part 3, NRCC 17409 edn. (National Research Council Canada, 1983)
E.S. Webster, Int. J. Thermophys. (2015) (in press)
F. Jahan, M. Ballico, Int. J. Thermophys. 31, 1544–1553 (2010)
R.E. Bentley, Theory and Practice of Thermoelectric Thermometry, 1st edn. (Springer, Singapore, 1998)
I. Jursic, S. Rudtsch, Int. J. Thermophys. 35, 1055–1066 (2014)
R.E. Bentley, Aust. J. Instrum. Control 4, 4–9 (1989)
M. Gotoh, in Temperature, Its Measurement and Control in Science and Industry, Part 1, vol. 7, ed. by D.C. Ripple, (AIP, New York, 2002), pp. 481–484
E.S. Webster, D.R. White, H. Edgar, Int. J. Thermophys. 36, 444–466 (2014)
E.S. Webster, Int. J. Thermophys. 35, 574–595 (2014)
T.G. Kollie, J.L. Horton, K.R. Carr, M.B. Herskovitz, C.A. Mossman, Rev. Sci. Instrum. 46, 1447–1461 (1975)
A.W. Fenton, in Temperature, Its Measurement and Control in Science and Industry, Part 3, vol. 4, ed. by H.H. Plumb (Instrument Society of America, Pittsburgh, 1972), pp. 1973–1990
N.A. Burley, R.M. Hess, C.F. Howie, J.A. Coleman, in Temperature, Its Measurement and Control in Science and Industry, Part 2, vol. 5, ed. by J.F. Schooley (Instrument Society of America, Pittsburgh, 1982), pp. 1159–1166
D.D. Pollock, Thermocouples Theory and Properties (CRC Press, Boca Raton, 1991)
G. Machin, K. Anhalt, F. Edler, J. Pearce, M. Sadli, R. Strnad, E. Vuelban, in 16th International Congress of Metrology (EDP Sciences, 2013)
R.E. Bentley, Measurement 23, 35–46 (1998)
K.D. Hill, Metrologia 31, 51–58 (2002)
Y.G. Kim, K.S. Gam, J.H. Lee, Meas. Sci. Technol. 8, 317–321 (1997)
R.E. Bentley, Meas. Sci. Technol. 12, 1250–1260 (2001)
O. Ongrai, J. Pearce, G. Machin, S. Sweeney, Int. J. Thermophys. 31, 1506–1516 (2010)
J. Tamba, K. Yamazawa, S. Masuyama, H. Ogura, M. Izuchi, Int. J. Thermophys. 32, 2436–2451 (2011)
G. W. Burns, M. G. Scroger, G. F. Strouse, M. C. Croarkin, W. F. Guthrie, in Temperature-Electromotive Force Reference Functions and Tables for the Letter-Designated Thermocouple Types Based on the ITS-90 (NIST, 1993)
R.E. Bentley, Meas. Sci. Technol. 11, 538–546 (2000)
P. Kinzie, Thermocouple Temperature Measurements, 1st edn. (Wiley, New York, 1973)
F. Edler, P. Ederer, in Temperature, Its Measurement and Control in Science and Industry, Part 1, vol. 8, ed. by C.W. Meyer, (AIP, New York, 2013), pp. 532–537
M. Rubel, Mater. Sci. Eng. 9–12 (1987)
J.C. Chaston, Platin. Met. Rev. 9, 51–56 (1965)
J.C. Chaston, Platin. Met. Rev. 19, 135–140 (1975)
T. Li, E.A. Marquis, P.A.J. Bagot, S.C. Tsang, G.D.W. Smith, Catal. Today 175, 552–557 (2011)
J.C. Chaston, Platin. Met. Rev. 8, 50–54 (1964)
J.C. Chaston, Platin. Met. Rev. 10, 91–93 (1966)
R.E. Bentley, Int. J. Thermophys. 6, 83–99 (1985)
F. Edler, A.C. Baratto, Metrologia 42, 201–207 (2005)
J.V. Pearce, H. Ogura, M. Izuchi, G. Machin, Metrologia 46, 743–749 (2009)
Y. Kim, I. Yang, K. Gam, Instrum. Sci. Technol. 36, 257–266 (2008)
E.H. McLaren, E.G. Murdock, Temperature, Its Measurement and Control in Science and Industry, Part 3, vol. 4, ed. by H.H. Plumb (Instrument Society of America, Pittsburgh, 1972), pp. 1543–1560
E.H. McLaren, E.G. Murdock, Temperature, Its Measurement and Control in Science and Industry, Part 2, vol. 5, ed. by J.F. Schooley (Instrument Society of America, Pittsburgh, 1982), pp. 953–975
R.E. Bentley, Meas. Sci. Technol. 12, 627–634 (2001)
Acknowledgments
The author wishes to acknowledge the financial assistance and resources provided by NPL in completing this work.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Webster, E., Mason, R., Greenen, A. et al. A System for High-Temperature Homogeneity Scanning of Noble-Metal Thermocouples. Int J Thermophys 36, 2922–2939 (2015). https://doi.org/10.1007/s10765-015-1939-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10765-015-1939-7