Development of a Fast Response, High Accuracy, and Miniaturized Fiber Bragg Grating (FBG) Sensor for Fluid Temperature Measurement

To address the specific requirements for fluid temperature measurement by aerospace equipment under unique operational conditions, a miniature, fast-response, high-precision pipeline fiber Bragg grating (FBG) fluid temperature sensor was developed in this study. The sensor structure was theoretically modeled, simulated, and optimized to meet size, weight, response rate, and accuracy criteria. The results indicate that the sensor with dimensions of $\Phi 1.98\times26.04$ mm and a weight of 93.37 g exhibits a response time of 1.94 s, a sensitivity of 29.16 pm/°C, accuracy of 0.2 °C, and linearity exceeding 0.9997. The sensor is compact and lightweight, exhibits good linearity and repeatability, and responds rapidly to temperature changes. Furthermore, it withstands acceleration of 6.5 g and vibration loads up to 2000 Hz. This study provides a valuable reference for the engineering applications of fiber optic FBG temperature sensors on spacecraft.