瞬态热带恒功率法测量导热率

基于传统热桥法基本原理,提出了新的非对称结构模型--瞬态热带恒功率法用于测量材料的导热率。非对称结构模型将热源热带与温度传感热带电路彼此独立,消除了热带电阻自热以及环境温度变化带来的影响。通过短时间内快速测量恒流电路中两热带的电压差随时间的变化关系准确测量材料的导热率。依据此模型设计了热带加热片,建立了基于LabVIEW测试软件的实验装置自动测量平台,实验测量结果与参考材料导热率具有良好的一致性,相对偏差在3％左右,验证了该理论模型的有效性。

Measurement of Thermal Conductivity Using Transient Hot-strip Method of Constant Power

Based on the traditional transient hot-bridge sensor,a new unsymmetrical model to measure thermal conductivity—the transient hot-strip method of constant power is proposed. This model insulated the heat source and the thermometer,eliminating the influence of self-heating from strips and the ambient temperature variations. By measuring the voltage change verse time,the thermal conductivity of the material can be obtained accurately. With this method,the corresponding heat sensor is designed,and the auto measurement platform of experimental system based on LabVIEW is established. By using this platform,the thermal conductivities of several normal materials are tested. Satisfactory consistent between the values obtained here and the reference values,the relative deviation is about 3% ,and the validity of the theoretical model is verified.