Abstract The laser flash technique is a standard method to measure the thermal diffusivity of solid samples especially at high temperatures. To understand the reliability of thermal diffusivity evaluation at high temperature for solid samples with low-thermal-diffusivity values, we analyzed the effect of radiative heat loss using the logarithmic method. The results revealed that when the Biot number was 0.1, the deviation from the input thermal diffusivity value was approximately −1.6%. In addition, when an aluminum silicate (AS) sample was heated to 1,273 K, the maximum deviation was approximately −0.35%. In contrast, the difference between the input value and the thermal diffusivity evaluated by the halftime method when AS was heated to 1,273 K was approximately 2.38%. Thus, since the effect of radiative heat loss was found to be negligible, it is concluded that the normalized logarithmic method should be very useful for the thermal diffusivity analysis of low-thermal-diffusivity solid samples at high temperature.

中文翻译：

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在激光闪光技术中使用归一化对数法评估辐射热损失对热扩散率的影响

摘要 激光闪光技术是测量固体样品热扩散率的标准方法，尤其是在高温下。为了了解热扩散率值较低的固体样品在高温下评估热扩散率的可靠性，我们使用对数方法分析了辐射热损失的影响。结果表明，当 Biot 数为 0.1 时，与输入热扩散率值的偏差约为 -1.6%。此外，当硅酸铝 (AS) 样品加热到 1,273 K 时，最大偏差约为 -0.35%。相比之下，当 AS 加热到 1,273 K 时，输入值与通过半衰期法评估的热扩散率之间的差异约为 2.38%。因此，由于辐射热损失的影响可以忽略不计，