In situ measurements of anisotropic heat conductivity

The subject of this paper is a development of a rapid, in-situ method of retrieving the orthotropic heat conductivity. The technique can be seen as an enhancement of the known Parkers flash technique [1]. The presented technique is capable of handling orthotropic media of arbitrary shape, provided the measurement surface is planar and two principal axes of the heat conductivity tensor are in that plane. The need for determining anisotropic conductivity arises when dealing with a certain type of crystalline materials like carbon but also when evaluating the equivalent conductivity of composites. The proposed method uses an infrared camera to record the variation of the temperature field induced by a laser impulse. Both the camera and the laser are located on the same side of the body under investigation.