The measurements of the thermal conductivity of HFC-134a have been carried out near the saturation line in the liquid phase from 172K to 294K and in the solid phase from 130K to 172K by the transient hot-wire method with an uncertainty of less than ±2%. The thermal conductivity in the solid phase and in the liquid phase is almost continuous. The experimental data in the solid phase have been represented as a function of temperature by the equation (2).

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A differential laser flash calorimeter was developed to measure specific heat capacity of solid materials up to high temperatures. The specimen to be measured is placed close to the reference specimen of known heat capacity side by side. Surfaces of both specimens are coated with the same black thin layer in order to get the same absorptance for the laser beam and the same spectral emissivity for radiation thermometry.
The front surfaces of both specimens are heated by a uniform beam from a pulse YAG laser and the change of spectral radiance from each specimen is observed with a high speed radiation thermometer. The heat capacity of the measured specimen is calculated from the ratio of the radiance change for two specimens and the heat capacity of the reference specimen.
Specific heat capacity of graphite and carbon/carbon composite was successfuly measured from the room temperature to 1700K. The measured specific heat capacity of the carbon/carbon composite is consistent with a differential scanning calorimetry measurement from the room temperature to 500K.

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A non-contact measuring method of thermal conductivity and diffusivity of an isotropic material is proposed. This method is based on the fact that the surface temperature variation with time depends on the material thermal properties when its surface is heated locally. In the experiment, the material surface is heated by laser beam and its temperature distributions are measured with an infrared thermometer. Acrylic resin, vinyl chloride resin, bakelite and silicon rubber are used as the test materials whose thermal properties are well known. From numerical simulations, it is found that the present method could measure the thermal conductivity and diffusivity of isotropic materials within erros of 7% and 15% for ΔT_c=20K, the surface central temperature rise at 3 seconds after step heating, when the measuring errors of peak heat flux q_p, heating radius r and surface temperature rise ΔT_w are assumed to be within 2%, 3% and 0.2K, respectively. This method could be applied to the measurement of thermophysical properties of biological tissues.

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[in Japanese]

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