Development Of Some Key Technologies For Thermal Constant Analyzer Based On Transient Plane Source Method

Transient Plane Source Method is an advanced method developed in recent years for measuring thermal properties of materials.It has the advantages of wide measuring range,high efficiency and versatile sample applicability.After some years of research,our group has successfully developed a prototype of TPS-based thermal constant analyzer.Though the instrument has the function of measuring the thermal conductivity of solid block,thin plate,film and other samples,with a relative good measurement accuracy of within 5%,for some material with larger thermal conductivity,such as copper,the measurement accuracy is about 10%,which is rather large.In addition,with the expansion of TPS technology,the demand for thermal constant measurement of materials in higher temperatures is increasingly prominent.However,no systematic studies have been conducted in high temperatures.Finally,the instrument doesn’t have the specific heat capacity measurement function.Based on the above problems,the main work of this thesis is as follows.1.Through reviewing the current research status of TPS theory and instruments domestically and abroad,the main problems to be solved are clarified,and the research contents and research objectives are put forward.2.For the problem of large measurement error in the measurement circuit,through the analysis of TPS measuring circuit and experimental data,it is found that the measurement error is due to the standard resistor paralleled with the TPS probe in the electronic circuit.Corresponding compensation model is given by studying the temperature characteristics of the standard resistor.The compensation model increased the measurement accuracy for samples with larger thermal conductivities to within 5%.3.Developed TPS higher temperature measurement technology.Based on the measurement principle of TPS method,a high temperature test probe was designed and a high temperature test system was built.After correcting the calibration of the high temperature probe and compensating for the heat loss of the probe and the heat loss of the lead,the corresponding correction model is summarized.After the correction model is introduced,the measurement error of the high temperature probe at room temperature is kept within 5%.Finally,the thermal conductivity of the standard material glass-ceramic Pyroceram 9606 was measured at high temperature.The relative error at various temperatures was less than 5%,and the repeatability was within 2%,thus verifying the validity of the TPS higher temperature measurement technology.4.Developed TPS specific heat capacity measurement technology.Through the analysis of the basic principle of TPS method and the principle of specific heat capacity measurement,the formula for measuring the specific heat capacity of materials by TPS method is derived,and the corresponding algorithm and experimental device are designed.Then,the specific heat capacity of PMMA,stainless steel,pure aluminum and copper were measured.The relative error of the measurement results was less than 5% compared with the reference values reported in the literature,and the measurement repeatability was within 2%,indicating that the system has favorable measurement results.5.Summarize the thesis and give prospects.