Lee Seung-Min
Devices and Materials System Laboratory, LG Electronics Advanced Research Institute, Seoul 137-724, Republic of Korea.
Rev Sci Instrum. 2009 Feb;80(2):024901. doi: 10.1063/1.3082036.
We have developed a procedure to measure the thermal conductivity of dielectric liquids and gases using a steady state ac hot wire method in which a thin metal wire is used as a heater and thermometer. The temperature response of the heater wire was measured in a four-probe geometry using an electronic circuit developed for the conventional 3omega method. The measurements have been performed in the frequency range from 1 mHz to 1 kHz. We devised a method to transform the raw data into well-known linear logarithmic frequency dependence plot. After the transformation, an optimal frequency region of the thermal conductivity data was clearly determined as has been done with the data from thin metal film heater. The method was tested with air, water, ethanol, mono-, and tetraethylene glycol. Volumetric heat capacity of the fluids was also calculated with uncertainty and the capability as a probe for metal-liquid thermal boundary conductance was discussed.
我们开发了一种使用稳态交流热线法测量介电液体和气体热导率的程序，其中细金属丝用作加热器和温度计。使用为传统的3ω法开发的电子电路，在四探针几何结构中测量加热丝的温度响应。测量在1 mHz至1 kHz的频率范围内进行。我们设计了一种方法，将原始数据转换为众所周知的线性对数频率依赖性图。转换后，热导率数据的最佳频率区域清晰可辨，这与来自金属薄膜加热器的数据处理方式相同。该方法用空气、水、乙醇、单乙二醇和四乙二醇进行了测试。还计算了流体的体积热容及其不确定度，并讨论了其作为金属 - 液体热边界传导探针的能力。
