The Error Analysis of a Steady-State Thermal Conductivity Measurement Method With Single Constant Temperature Region

2006 ◽  
Vol 129 (9) ◽  
pp. 1119-1126 ◽  
Author(s):  
Ming-Tsung Sun ◽  
Chin-Hsiang Chang
Keyword(s):  
Thermal Conductivity ◽  
Steady State ◽  
Numerical Model ◽  
Constant Temperature ◽  
Temperature Region ◽  
Conductivity Measurement ◽  
Thermal Conductivity Measurement ◽  
Dimensional Approximation ◽  
The One ◽  
Single Constant

Abstract A method for steady-state thermal conductivity measurement with single constant temperature region has been developed. To better understand the accuracy of the method a numerical model is devised and verified by experimental results. The ratios of thermal conductivity derived from the temperature distribution solutions to that given in the numerical model are obtained and shown. They can be used to correct the systematic error of measurement introduced by the one-dimensional approximation. Finally, the measurement uncertainty due to misalignment of the temperature sensors and the limitation of sensing devices is also investigated. The numerical model is suitable for estimating the range of confidence in practical measurements.

An Accuracy Analysis of the Steady-State Thermal Conductivity Measurement Method With Single Constant Temperature Region

2003 ◽  
Author(s):  
Ming-Tsung Sun ◽  
Chin-Hsiang Chang
Keyword(s):  
Thermal Conductivity ◽  
Steady State ◽  
Temperature Distribution ◽  
Constant Temperature ◽  
Temperature Region ◽  
Relative Size ◽  
Conductivity Measurement ◽  
Thermal Conductivity Measurement ◽  
Homogeneous Material ◽  
Single Constant

The newly developed method for steady-state thermal conductivity measurement with single constant temperature region is experimentally proven accurate within 3% compared with the guarded hot plate method. The method is suitable for in-situ non-destructive evaluation of insulation materials. However, there are factors that affect the accuracy of measurement yet to be closely studied. In this paper, we present a theoretical analysis of the accuracy of the method by varying the relative size of the heating plate, the thickness of the test specimen, the location of the temperature sensors at the lower temperature side, and different thermal convection coefficients for the free convection boundary condition. In the study, the temperature distribution in a homogeneous material is solved numerically. The thermal conductivity is evaluated from the temperature distribution and the heat flux measured according to the method. By comparing the results with that given in the numerical model, the accuracy can be expressed as functions of the three variables in the analysis. The results are consistent with that of the experiment. They are considered beneficial in providing information to the optimal design and the measurement correction of a commercialized apparatus using the method.

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