The present paper addresses the measurement errors in temperature due to the effects of surface-mounted temperature sensors like thermocouples. Heat conduction into or from the installed thermocouple wires can alter the temperature at the thermocouple junction as well as in its immediate vicinity. As a result, the emf appearing at the thermocouple terminals does not correspond to the actual surface temperature. In this paper, we present a dual-scale computational method that can be used to calculate the transient temperatures at the multiple thermocouple junctions during heating or cooling of an object. The basis of the method is a thermocouple submodel embedded in a FEM model for the parent object. The numerical results of the dual-scale computational model are compared with that of the conventional FEM models as well as the analytical solutions available. This paper also discusses the characteristics of surface-mounted thermocouples in a range of configurations.

1.
Saraf, V., 2001, “Distortion Characterization and Quench Process Modeling in Heat Treated Components of IN 718 Superalloy and AISI 4142 Steel,” M.S. thesis, Department of Mechanical, Materials and Aerospace Engineering, Illinois Institute of Technology, Chicago, IL.
2.
Cross, M. F., Bennett, J. C., Jr, and Bass, R. W., 1999, “Developing Empirical Equations for Heat Transfer Coefficients on Metallic Disks,” 19th ASM-HTS Conference Proceedings, pp. 335–342.
3.
Park, J. E., Childs, K. W., Ludtka, G. M., and Chu, W., 1991, “Correction of Errors in Intrinsic Thermocouple Signals Recorded During Quenching,” National Heat Treat Conference, Minneapolis, MN.
4.
Zhou, G. F., and Tszeng, T. C., 2002, “Determination of Heat Transfer Coefficients by Inverse Calculation in Conjunction With Embedded Model for Surface Mounted Thermocouples,” paper in preparation.
5.
Tszeng
,
T. C.
, and
Saraf
,
V.
,
2003
, “
A Study of Fin Effects in the Measurement of Temperature Using Surface Mounted Thermocouples
,”
ASME J. Heat Transfer
,
125
, pp.
926
935
.
6.
Gummadam, K. C., 2002, “Characterizing the Inverse Computational Method for the Determination of Surface Heat Transfer Coefficients,” M.S. thesis, Department of Mechanical, Materials and Aerospace Engineering, Illinois Institute of Technology, Chicago, IL.
7.
Bass, R. W., 1998, Heat Transfer of Turbine Disks in Liquid Quench, Techxperts, Inc., Tolland, CN.
8.
Tszeng, T. C., 2000, “Determination of Heat Transfer Boundary Conditions of Quenching Operations in Heat Treating Processes,” Heat Treating and Hardening of Gears, SME Technical Paper CM00-123, SME, Dearborn, MI.
9.
Beck, J. V., and Osman, A. M. 1992, “Analysis of Quenching and Heat Treating Processes Using Inverse Heat Transfer Method,” Proceedings of the First International Conference on Quenching and Control of Distortion, G. E. Totten, ed., ASM International, pp. 147–153.
10.
Beck, J. V., Blackwell, B., and St. Clair, Jr., C. R., 1985, Inverse Heat Conduction: Ill-Posed Problems, Wiley-Interscience, New York.
11.
Gummadam, K. C., and Tszeng, T. C., 2001, “An Integrated Approach to Estimate the Surface Heat Transfer Coefficients in Heat Treating Processes,” ASM International/IFHTSE Symposium on Quenching and Control of Distortion.
12.
Moffat, R. J., 1962, The Gradient Approach to Thermocouple Circuitry, From Temperature—Its Measurement and Control in Science and Industry, Reinhold, New York.
13.
Hennecke
,
D. K.
, and
Sparrow
,
E. M.
,
1970
, “
Local Heat Sink on a Convectively Cooled Surface—Application to Temperature Measurement Error
,”
Int. J. Heat Mass Transfer
,
13
, pp.
287
304
.
14.
Shi, G., Tszeng, T. C., and Nash, P., 2003, “
Modeling of the Austenitization in a Lamellar Pearlite Microstructure of Eutectoid Steels at High Temperatures,” Mater. Sci. Eng., A, in press.
15.
Sparrow, E. M., 1976, Measurement in Heat Transfer, 2nd ed., E. R. G. Eckert and R. J. Goldstein, eds., Hemisphere Publishing Corp, Chap. 1.
16.
Keltner
,
N. R.
, and
Beck
,
J. V.
,
1983
, “
Surface Temperature Measurement
,”
ASME J. Heat Transfer
,
105
, pp.
312
318
.
17.
Litkouhi
,
B.
, and
Beck
,
J. V.
,
1985
, “
Intrinsic Thermocouple Analysis Using Multinode Unsteady Surface Element Method
,”
AIAA J.
,
23
, pp.
1609
1614
.
18.
Segall
,
A. E.
,
1994
, “
Corrective Solutions for Intrinsic Thermocuples Under Polynominal Substrate Loading
,”
ASME J. Heat Transfer
,
116
, pp.
759
761
.
19.
Tszeng, T. C., 2001, HOTPOINT System Manual, 2001, Illinois Institute of Technology, Chicago, IL.
20.
Arpaci, V. S., 1966, Conduction Heat Transfer, Addison-Wesley Publishing Co., Reading, MA.
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