Research On Static And Dynamic Characteristics Of High Temperature MEMS Thermocouple Excited By Laser

Temperature testing in the aerospace,industry production and the chemical metallurgy and other fields has a very wide application,especially for high temperature and high pressure and high impact extremely accurate temperature measurement of the transient conditions has more strong realistic meaning.Thermocouple with its unique characteristics of cap of a wide range of high temperature measurement and become a transient one of the most common type of temperature sensor in high temperature environment,but because of the presence of delay often leads to temperature measurement delay,and cause the problem of inaccurate measurement results Therefore to carry out the higher temperature faster performance of developing thin-film thermocouple and its static and dynamic characteristics of the research is of important value.Existing in the current study of MEMS temperature sensor at home and abroad,this paper proposes a magnetron sputtering method is used to design method of C type tungsten-rhenium thin-film thermocouple based on Comsol software simulated its hot nodes in transient high temperature environment,dynamic response and analyzed in the experiment of different sputtering power,sputtering pressure,oxygen,argon flow rate and annealing process of different influence on the performance of the thin-film thermocouple,it is concluded that the best process parameters,provides reference for the study of the thin-film thermocouple and preparation.The time constant of a thermocouple is an important indicator to reflect its dynamic performance.In order to solve the problem of obtaining quantitative step signal in the measurement of the time constant of a thermocouple,a high-power semiconductor laser with microsecond pulse width leading edge of heating energy source is designed.Back to infrared detection module and integration of dynamic and static calibration conjugate no aberration big ellipsoidal mirror test system composed of optical module,PID and Tornambe two different negative feedback control algorithm to control the output power of laser,and thermocouple temperature measurement of the dynamic temperature balance,from the dynamic response curve of thermocouple to obtain its time constant.Two different control algorithms are used to test the time constant of the thin film thermocouple.The results show that the Tornambe control algorithm has better control performance than the traditional PID control algorithm,which can realize the stability of the thermocouple response signal more quickly,the speed increased by 37.61% and has a better ability to adjust some uncertain disturbances in the system.Finally,in the same test system,the negative step signal excitation method is combined to carry out the cross validation of different test methods,which improves the reliability of the test results.