Development Of An ARM-based Electronic System For Thermal Conductivity Measurement Using Guarded Hot Plate Method

Thermal conductivity is one of the most important thermal parameters,and accurate measurement of the thermal conductivity is of great significance for the development of building energy,materials research,aerospace and other fields.The Guarded Hot Plate(GHP)method is one of the most accurate methods for measuring the thermal conductivity of materials.It has the advantages of high measurement accuracy and wide measurement temperature range.At present,the laboratory has developed a Guarded Hot plate thermal conductivity measuring instrument.However,there are still problems in its electronic systems and software,such as old electronic systems,long time-consuming production and debugging,and insufficient measurement accuracy.Therefore,the development of electronic systems for thermal conductivity instruments is of great significance.The content of this thesis is as follows:1.Firstly,the basic concepts of heat transfer and thermal conductivity are introduced.Then,a brief description of the development status and trends of the Guarded Hot Plate at home and abroad is given.Then the existing problems of the thermal conductivity measuring instrument in the laboratory were analyzed and the main content of the article was introduced.2.Introduce the basic principles of heat transfer and lay a basic theoretical foundation.The Fourier one-dimensional heat transfer model based on the Guarded Hot Plate method is analyzed.The measurement principle of the Guarded Hot Plate method is described.Finally,the overall design of the instrument is introduced.3.The electronic control system of the thermal conductivity measuring instrument was designed,the sensor was selected,the temperature acquisition circuit was designed,and the heating circuit,communication circuit and power supply circuit were designed.4.The temperature acquisition LTC2983 chip was configured and the computer control program was programmed.5.We designed the experiment to calibrate the thermal conductivity measuring instrument,including calibration of the temperature sensor,calibration of the board temperature,and calibration of the control output voltage.Design multiple sets of experiments to analyze the test results of the thermal conductivity measuring instrument.6.Summarize the research work and content of this topic,and analyze the problems of the instruments for future improvement.