A Thermometry System Based On Sapphire Fiber Blackbody Method

In the field of military and national defense,it is necessary to monitor the explosion process.However,it is difficult to measure the temperature of explosion because of its high temperature,great impact and short duration.To measure the explosure temperation,non-contact thermometry is adopted throughout the world.Even though it has the advantages of high speed and wide range,it is not a sufficient way on account of the low accuracy and the imprecision of the measurement target etc.However,the sapphire fiber blackbody temperature measurement method has the characteristics of high accuracy,fast response and high temperature resistance,which exactly meets the needs of explosion flame thermometry.The dissertation derived from a joint project of the Institute of Automation Process and Control of Harbin Institute of Technology and a national research institute.According to the demand,this paper analyzes the advantages and disadvantages of various methods of temperature measurement,and eventually developes a sapphire fiber blackbody temperature measuring instrument for explosion flame.Firstly,the principle of Sapphire Fiber Blackbody method is introduced in detail,and the overall scheme of thermometer is completed.Secondly,on the surface of the sapphire fiber blackbody cavity is simulated and designed to determine the molybdenum and boron nitride as sapphire fiber blackbody cavity materials.According to the simulation results of ANSYS,the actual thickness of the blackbody cavity is determined.Thirdly,photoelectric conversion,amplification circuit and data acquisition of temperature measuring system are designed as hardware modules.Fourthly,the software module of the thermometer is designed on the platform of Lab VIEW.The user interface is simple and easy to use,and it can realize the display and preservation function of data.Finally,the calibration of temperature of the system is finished using a high temperature furnace,the standard equations of the sensors are fitted out in Matlab.The dynamic response experiment is performed with high-speed pulse laser.Then the instrumental error uncertainty of the temperature measurement system are analyzed.