| Thermal performance of heat-resistant material is essential in aircraft design which has a direct impact on the safety performance of aircraft. In order to prevent the destruction and damage caused by high aerodynamic heating, the ground simulation equipment and the temperature measurement system for high temperature measuring are urgently needed. Known as the vanguard of Aeronautics and Astronautics, wind tunnel is a piece of effective ground simulation equipment which was used to study the relative motion and the interaction law between air and objects. Temperature is acting as an important parameter affecting material properties. Temperature measurement of heat-resistant material of the simulated aircraft can help the designers select the appropriate materials to produce aircrafts. The Institute of Automatic Detecting and Process Control System (D&CS) of Harbin Institute of Technology has been working on the temperature measurement of heat-resistant material of aircrafts simulated in wind tunnel test, which was commissioned by China Aerodynamics Research and Development Center and High-speed Aerodynamic Institute. This study had practical significance on improving safety reliability of the aircrafts, and promoting the development of the technology of high-precision temperature measurement.Since the simulation of aircraft was often carried on under high pressure, high current, and other dangerous situations, high temperature measurement cannot rely on traditional manual contact detection method. Moreover, there was an infrared window which can transmit infrared between 3 and 5μm in the electric arc wind tunnel. Based on this situation, the dissertation used the improved Colorimetry which not only reduced the interference of water vapor and dust in the light path, but also reduced the influence caused by the change of radiation rate of the testing area. With the benefits of low cost and high precision, this method had an unparalleled advantage over other emissivity compensating methods.The main work contained the design and debug of hardware system and software system, the calibration test of pyrometer, the vision test and the test on site. The hardware system could be divided into two parts: the optical channel and the circuit design. The energy radiated by the target was sampled by lens, dispersed by half-reflecting planemirror and then reached the infrared detector, in which it was transformed into electrical signal. The signal transitted preamp, phase-locked amplifier and was collected by data acquisition card USB-7360. The acquired data were then stored and processed in the embedded systems PC104. The software was programmed by LabVIEW graphic language, which can speed up the development of programs and is easy to study. This paper proposed the energy method in the calibration of the pyrometer which improved the measurement accuracy of this instrument.The system prefered the detector of which typical response spectrum is between 3 and 5μm which completely covered the infrared window in wind tunnel test, to avoid the large interference of the visible band. This pyrometer could achieve effective detection whenφ1mm object was measured from a distance of 1m, namely, the distance coefficient of 1000:1. Moreover, the system ingeniously eliminated the stray light which made the perfect optical system. Therefore, the perfect hardware drive and powerful data processing made the measurement system work steadily and have a strong anti-interference capability.
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