 Fig.1 Temperature distribution by thermographic measurement |
 Fig.2 Temperature distribution determined by FEM |
 Fig.3 Relationship between slope of grain and LS ratio |
1998
When the longitudinal surface of wood is heated within a small circle, it must show an elliptical pattern of temperature rise around the heat source elongated along the grain due to the thermal anisotropy of wood. This implies that the slope of grain could be estimated by a thermographic technique including the thermal stimulation of surfaces and the temperature measurement by an infrared camera. The feasibility of this technique was examined theoretically using finite element method (FEM) and experimentally for wood surfaces heated by a hot cylinder of brass with a diameter of 5 mm.
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Fig.1 Temperature distribution by thermographic measurement |
Fig.2 Temperature distribution determined by FEM |
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Fig.3 Relationship between slope of grain and LS ratio |