Line-source method, polymer thermal

Lobo, H. and Cohen, C., Measurement of Thermal Conductivity of Polymer Melts by the Line-Source Method, Polym. Eng. Set, 30, 65 (1990)... 

Lobo H, Cohen C. Measurement of thermal conductivity of polymer melts by the line-source method. Polym Eng Sci 1990 30(2) 65-70. 

The line-source technique is a transient method capable of very fast measurements. A line source of heat is located at the center of the sample being tested as shown in Fig. 4. The whole is at a constant initial temperature. During the course of the measurement, a known amount of heat is produced by the line source, resulting in a heat wave propagating radially into the sample. The rate of heat propagation is related to the thermal diffusivity of the polymer. The temperature rise of the line somce varies linearly with the logarithm of time. Starting with the Fourier equation, it is possible to develop a relationship which can be used directly to calculate the thermal conductivity of the sample from the slope of the linear portion of the curve ... 

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