Research And Application Of High Temperature Sensor

Temperature is a fundamental physical quantity, which is the most common andimportant technical parameters in the production process. Many aspects such as the industrialand agricultural production, scientific research and national defense modernization areinseparable from temperature measurement. However, accurate temperature, especiallyaccurate surface temperature, is not easy to measure even by thermometer withhigh accuracy. It’s very difficult to get the desired results if the measurement method is notappropriate or the measurement environment can not meet the requirements. Hence greatconcern is focused on the accuracy measurement of high temperature.Temperature is a very important test parameter the fields of aerospace and military.When ballistic missiles, reentry aircrafts, space operation aircrafts and hypervelocity cruisemissiles fly with hypersonic speed (Ma number is more than five), strongaerodynamic heating phenomenon appears due to the air viscosity effect, making thetemperature around the aircraft increase rapidly. Accurate measurement of the temperature iscrucial to the design of heat insulation structure and the work reliability of internalaircraft instrument. We adopt the method of contact measurement for the flight environmentis of great complexity.We should choose and design appropriate high temperature sensor in the process ofsurface measurement of high temperature. And we also do such signal processing as coldjunction compensation, linearization, amplification to gain standard voltage or current signal.It is easy to facilitate long-distance signal transmission and calibrate the temperaturemeasurement system, in order to ensure that the sensor performance index meets therequirements.After selecting the suitable temperature measurement system, this paper makes adetailed research to the test system, aircraft structure and aircraft flight environment according to the requirement proposed in the mission paper, which is about how to measure the outerwall temperature of the hypersonic aircraft accurately. Then the reason is analyzedtheoretically why there is a big error exists in the temperature measurement. Reasonableassumption of the temperature measurement environment is brought forward according to theheat transfer theory finding the reason. The actual temperature of the outer wall can bespeculated by the inner temperature of the aircraft. High-temperature simulation of the wholeprocess is carried to verify the rationality and accuracy of the assumption and calculation, andANSYS is used to have a transient thermal simulation analysis on the heat transfer process.There is still error on the obtained final results after the process of experiment, calculation andsimulation, but this kind of error is accepted in engineering calculation.