Abstract:The thermal diffusivity measurement method of the thin specimens based on thermography technology is researched and improved, and the theoretical model is developed from two-dimensional model to three-dimensional model, so that the materials with bigger thickness can be measured by this method.The characteristic condition, which must be satisfied when this measurement method can be used, is that the relationship between the spatial derivatives of temperature in Z-direction and temperature difference between the surface temperature of material and environmental temperature is a linear relation. The effects of conducting distance and excitation time on the characteristic condition are analyzed, and the relevant problems of signal to noise ratio by the simulation experiment are also studied. Setting the conducting distance and excitation time according to the simulation analysis when measure the thermal diffusivity of 304 stainless steel, the results show that the deviation of the measurement for the stainless steel with thickness of 1 mm and 2 mm is less than 3.0%, and the deviation of the measurement for the stainless steel with thickness of 5 mm is 4.1%, so the range of application of the measuring method is expand.
厉阳,侯德鑫,叶树亮. 基于热成像的材料热扩散率测量方法研究[J]. 计量学报, 2017, 38(1): 28-33.
LI Yang,HOU De-xing,YE Shu-liang. Research on Measurement Method of Thermal Diffusivity of Materials Based on Thermography. Acta Metrologica Sinica, 2017, 38(1): 28-33.
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