Abstract:
A novel aluminum plate based fiber Bragg grating (FBG) sensor is proposed to detect temperature and flowvelocity. Fiber Bragg grating (FBG) was sealed on an aluminum plate by a hightemperatureresistant glue, then placed in a thermostat for solidification so as to retain the stability of FBG. The temperature and flowvelocity sensing characteristics of the encapsulated FBG sensor were theoretically and experimentally studied. Encapsulated FBG sensor was placed in a digital thermostat to detect its temperature characteristics. In the temperature range of -20℃~100℃, the experiment result indicates that the temperature sensing sensitivity coefficient of encapsulated FBG sensor is 0.0392nm/℃ and is 3.5 times as much as that of bare FBG. The temperature response curve of the encapsulated FBG sensor keeps very good linearity and repetition. In the flowvelocity experiment, the reflection peakwavelength of the encapsulated FBG sensor moved 0.13nm when the flowvelocity changed from 0 to 20m/s with constant water temperature at 14.5℃. So it is feasible to use the encapsulated FBG sensor to detect the flowvelocity. The result proves that the aluminum plate encapsulated FBG sensor can detect temperature and flowvelocity. The encapsulated FBG sensor is easy to make, cost effective and practical.