0
TECHNICAL PAPERS: Measurement Techniques

A Study of Fin Effects in the Measurement of Temperature Using Surface-Mounted Thermocouples

[+] Author and Article Information
T. C. Tszeng, V. Saraf

Thermal Processing Technology Center, Department of Mechanical, Materials and Aerospace Engineering, Illinois Institute of Technology, Chicago, IL 60616

J. Heat Transfer 125(5), 926-935 (Sep 23, 2003) (10 pages) doi:10.1115/1.1597622 History: Received January 15, 2002; Revised April 22, 2003; Online September 23, 2003
Copyright © 2003 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Two types of junction for installing surface-mounted thermocouples
Grahic Jump Location
The simple two-dimensional axisymmetric model and FEM mesh for surface-mounted thermocouple on an object. The mesh only represents symmetric half of the domain. The top surface of the parent object and the thermocouple wire surface are exposed to the environment; all other surfaces are assumed to have zero heat flux (insulated). (a) Thermocouple wire diameter=0.4 mm; (b) Wire diameter=0.04 mm.
Grahic Jump Location
Distribution of temperature in the vicinity of thermocouple junction at 0.1 second in quenching. Initial temperature is 945°C. Wire diameter=0.4 mm
Grahic Jump Location
Temperature histories at the center and at the edge of the thermocouple junction, respectively. Wire diameter=0.4 mm. Also shown is the undisturbed temperature at the surface (at a location 5 mm from the center of the junction). (a) In the first 0.1 second; (b) In the first one second.
Grahic Jump Location
Temperature histories at the center and at the edge of the thermocouple junction, respectively. Wire diameter=0.04 mm. Also shown is the undisturbed temperature at the surface (at a location 5 mm from the center of the junction).
Grahic Jump Location
Comparison of the fin effects between thermocouples of different wire diameter. The temperatures at the center of the junction for both cases are shown.
Grahic Jump Location
Experimental results from two surface-mounted K-type thermocouples on a 4142 steel disk with two different wire diameters of 0.32 mm and 0.038 mm, respectively
Grahic Jump Location
Temperature histories at the center and at the edge of the insulated thermocouple junction, respectively. Wire diameter d=0.4 mm. Also shown is the undisturbed temperature at the surface (at a location 5 mm from the center of the junction).
Grahic Jump Location
Embedded computational model for calculating the temperature field in and around the thermocouple
Grahic Jump Location
Mesh system used in conjunction with the embedded computational model for calculating the temperature field in and around the thermocouple corresponding to the examples of Fig. 2. The mesh shown is the right half of the actual axisymmetric part. The thermocouple is located at the upper left corner of the domain.
Grahic Jump Location
Temperature histories at the center of the thermocouple junction when submodel is used. Wire diameter and length are indicated in each case. There are two coinciding curves for the case of wire diameter of 0.4 mm; one from the submodel and the other from the full model of Fig. 2.
Grahic Jump Location
Temperature history at the center of each thermocouple mounted at different locations on the top surface of the parent object (Fig. 10). Wire diameter=0.04 mm. The exact locations of thermocouple are shown in Fig. 10; different location corresponds to different element size in the parent object.
Grahic Jump Location
Histories of surface temperature at locations of different distance from the center of the thermocouple junction; the distances are zero (center), one wire diameter, and two wire diameter. The parent object is in Fig. 10. (a) Wire diameter=0.4 mm, (b) wire diameter=0.04 mm.
Grahic Jump Location
Temperature history at the center of a thermocouple mounted at the center on the top surface of the parent object (Fig. 10). Wire diameter=0.04 mm. For the parent object, thermal conductivity k=15 W/m/K and heat capacity ρc=5×106J/m3/K. For the thermocouple material, thermal conductivity k has the values of 15, 5 or 0.005 W/m/K, and heat capacity ρc=5×106J/m3/K.
Grahic Jump Location
Instrumented Jominy end quench specimen that is 100 mm-in-length×25.5 mm-in-diam. Two thermocouples of intrinsic junctions are installed at the indicated locations. TC 1 is located at the center of the end; TC 2 is located on the lateral surface (unwetted) at a distance of 3.8 mm from the quenched end. Wire diameter is 0.25 mm, and spacing between the two junctions is one wire diameter.
Grahic Jump Location
Measured and calculated temperature at the thermocouple locations indicated in Fig. 14. The calculated temperatures are with or without the fin effects by the thermocouple wires. Wire diameter d=0.25 mm.
Grahic Jump Location
A comparison between the calculated surface heat transfer coefficient and that obtained by Buchmayr and Kirkaldy 21. The calculated HTC from the present study is plotted against the undisturbed surface temperature, not the temperature at the thermocouple junction. The calculated HTC only reached to about 200°C.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In