Multiple Measurements of Thermophysical Properties of Non-metallic Materials by a Transient Method

与金属材料相比，非金属材料半球面总发射率的测量研究很少。本文提出了一种用瞬态法同时测量非金属材料的半球总发射率、比热和热扩散系数的方法。在测量非金属材料的热物性时，存在着在所用样品中产生热梯度的问题。提出了一种改进的降低温度梯度的瞬态量热法，并以半透明玻璃片为测量对象，给出了以厚度为参数的测量结果。估算了局部半球发射度分布引起的样品拐角效应对测量总发射度的影响。结果表明，该方法对于测量非金属材料的半球总发射率、比热和热扩散系数是非常有用的。

There are very few investigations on the measurements of total hemispherical emittance of non-metallic materials, in contrast to those on metallic materials. In this investigation, a method for simultaneous measurement of total hemispherical emittance, specific heat and themal diffisivity of non-metallic materials by means of a transient method has been developed.On measurements of thermophysical properties of non-metallic materials, there arises a problem of the thermal garadient produced in a specimen used. An improved transient calorimetric technique to reduced the thermal gradient is proposed in this study.Glass sheets semi-transparent for radiation are selected as a measured by the proposed technique and their results are presented with the thickness as parameter. The corner effect of the specimens due to the local hemispherical emittance distribution on the measured total hemispherical emittance is estimated. It is shown that the proposed technique is very useful for measuring total hemispherical emittance, specific heat and themal diffisivity of non-metallic materials.