A preliminay investigation for detection of biodeteriorated location in wood by thermographic method was carried out. Ezomatsu (Picea jezoensis CARR.) wood having artificial boring or artificial internal cavity was used as model test specimens. Size of test specimens was 8.0 cm long at fiber direction by 6.8 cm high by 3.7 cm deep.
Current of heat was produced in test specimens to make evident the difference of thermal characteristics between each parts of test specimens, that is, sound part and bottom of the boring or upside of the cavity. At this experiment, current of heat was produced by making the test specimens to the room temperature, approx. 20°C, after cooling them to approx. -12°C or heating them to approx. 60°C. At these two stages, surface temperature changes of each parts of test specimens with passage of time was measured by "Thermograph".
As the results, followings were obtained at the rising or falling stages described above.
1) Rising or falling speed of temperature at the bottom of the artificial boring was low compared with these at the outside of the boring, that is, sound part. Therefore, possibility of thermographic detection of the surface boring in wood was observed.
2) Rising or falling speed of temperature at the upside of the artificial internal cavity, that is, on the plug, was similar to these at the outside of the plug, that is, sound part. Therefore, limitation of thermographic method was observed under the condition of measurements described above to detect the internal cavity in wood.
Further examinations and improvement about the method of producing the current of teat in the test specimens must be required to detect the internal deterioration and to put the thermographic detection to practical use.

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