Power modulation technique for noncontact high‐temperature calorimetry
Power modulation technique for noncontact high‐temperature calorimetry
复制标题
非接触式高温量热功率调制技术
DOI：
10.1063/1.109626
复制
发表时间：
1993
影响因子：
4
通讯作者：
R. Willnecker
中科院分区：
文献类型：
--
作者：
R. Wunderlich;H. Fecht;R. Willnecker
基于超高真空条件下功率调制射频场对金属球形块状样品的感应加热，开发了一种新的非接触式量热方法。根据高温测量的温度响应，发现样品的外部弛豫时间（由于辐射热损失）和内部弛豫时间（由于热导率）相差两个以上数量级，从而可以将样品的比热和热导率确定为温度的函数。固体铌的测量温度响应与预测温度响应之间的一致性证明了该方法的适用性和准确性，该方法对于高温下的亚稳态或化学反应性样品特别有用。
A new noncontact calorimetric method has been developed based on inductive heating of a metallic spherical bulk sample by a power‐modulated radio‐frequency field under ultrahigh vacuum conditions. From the pyrometrically measured temperature response the specimen’s external (due to radiative heat loss) and internal relaxation time (due to thermal conductivity) are found to differ by more than two orders of magnitude allowing the specific heat as well as thermal conductivity of the sample to be determined as a function of temperature. The agreement between the measured and predicted temperature response for solid Nb demonstrates the applicability and accuracy of the method which is particularly useful for metastable or chemically reactive samples at high temperature.