高灵敏度光纤温度传感器

针对深井温度变化小,提出了一种可用于深井温度测量的高灵敏度光纤温度传感器。两根陶瓷插芯从铝管的两端插入构成外腔式光纤法珀干涉仪(EFPI)结构,用螺钉固定插芯,再用高强度的环氧树脂密封该结构,达到防水防尘效果。金属铝和陶瓷插芯具有不同的热膨胀系数,温度的变化将引起EFPI腔长变化,采用高灵敏度光纤白光干涉测量技术,就可以通过测量EFPI腔长获得被测温度。分别在固定温度和不同温度下,对腔长为146.5μm的EFPI光纤温度传感器进行了连续测量。测量结果表明,高灵敏度EFPI光纤温度传感器的腔长-温度灵敏度为260nm/℃,温度测量分辨率为0.002℃。

An optical fiber temperature sensor with high sensitivity

An optical fiber temperature sensor with high sensitivity is presented for the measurement of small temper-ature change in the deep well .The structure of the sensor is an Extrinsic Fabry-Perot Interferometer (EFPI) with two ce-ramic ferrules inserted into the center from both ends of the aluminum tube .The ceramic ferrules are fixed with screws , and the high strength epoxy resin is used to seal the structure to achieve the effect of waterproof and dust prevention .A-luminum tube and ceramic cores have different thermal expansion coefficients ,and the change of temperature will cause the change of EFPI cavity length .Based on the high-sensitive optical fiber white light interferometry(WLI) ,the tempera-ture can be obtained by measuring the cavity length of the EFPI .The EFPI optical fiber temperature sensor with the cavi-ty length of 146 .5μm is continuously measured in a fixed temperature and different temperature .The results show that the sensitivity of the EFPI optical fiber temperature sensor designed has a temperature sensitivity of 260nm/℃ ,and a temperature resolution of 0 .002℃ .