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Accession number;07A0043241
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| Title;DEVELOPMENT OF A THERMAL DIFFUSIVITY STANDARD BY THE LASER FLASH METHOD (III) |
| Author;
AKOSHIMA MEGUMI
(National Inst. Advanced Industrial Sci. and Technol., JPN)
BABA TETSUYA
(National Inst. Advanced Industrial Sci. and Technol., JPN)
KATO HIDEYUKI
(National Inst. Advanced Industrial Sci. and Technol., JPN)
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Journal Title;Thermophys Prop
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Journal Code:X0031A
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ISSN:0911-1743
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VOL.27th;NO.;PAGE.115-117(2006)
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| Figure&Table&Reference;FIG.3, REF.8 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;The laser flash method is the one of the most popular method to measure thermal diffusivity of solid materials above room temperature. In many cases, thermal conductivity of material is calculated from the thermal diffusivity value measured by this method and the heat capacity value measured by the differential scanning calorimeter. The laser flash method is well established and the instruments are easy to use. However it is also known that the measured result by this method depends on measurement conditions. So, check using thermal diffusivity reference materials might give information about bias of thermal diffusivity measurement of practical laser flash instruments. The National Metrology Institute of Japan (NMIJ) has been studying the laser flash method in order to establish the SI traceable thermal diffusivity standard. The laser flash method is reliable because of the simple one dimensional heat diffusion phenomena. It can be analytical evaluation of uncertainty. NMIJ has made some technical improvements such as uniform pulse heating, infrared thermometry for this method, and original analysis algorism. And we have integrated these techniques and developed the standard measurement system. We have proposed the procedure to determine the intrinsic thermal diffusivity independent of measurement conditions and specimen thicknesses. At a fixed temperature, the thermal diffusivity values are measured with changing pulsed heating energy and plotted as a function of the temperature rise resulted from the pulsed heating energy. The intrinsic thermal diffusivity is determined as the value at the extrapolated to zero temperature rise. Evaluation of uncertainty has been carried out based on GUM. We have also developed the reference material for the laser flash method. We have selected some carbon materials as a candidate reference material because they can be measured without black coating. We have investigated homogeneity and stability of them.... (author abst.) |
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