Design Of Fiber Optics Temperature Sensors

In order to provide long-term and on-line real-time measurement of various engineering structures such as temperature of the aircraft wings, for the internal parameter measurements of composite materials and structures specimen, a new temperature sensor-embedded fiber optic interferometer temperature sensor is put forward in this paper. Using a special machining technology, the sensor is embedded in the fiber materials, so it can produce interference stripes by phase modulation. Through appropriate processing circuit to calculate the value of stripes movement and judge the direction of the movement, the variation of internal temperature of the material will be obtained. This paper is focused on the theoretical derivations of this kind of embedded interferometric fiber-optic temperature sensor which is applied to temperature measurement of composite materials, the relationship of the value of stripes movement and temperature is educed. The temperature of composite materials which are embedded in such sensors is measured. The experimental results and the discussion of the sources of error are given in this paper. The results of experiments show that the embedded fiber temperature sensors can be an effective long-term measurement for the internal temperature and their sensitivity is 2-3 times higher than in the air. So we can say that it has Great value of development and application, and has good prospects.