Li Guoli, Feng Fei, Qian Caihua, Wei Bo
School of Mechanical and Electrical Engineering, Jinling Institute of Technology, Nanjing, China.
School of Mechanical Engineering, Yancheng Institute of Technology, Yancheng, China.
PLoS One. 2025 Jan 31;20(1):e0317523. doi: 10.1371/journal.pone.0317523. eCollection 2025.
To solve the problems of low detection efficiency and inability to adapt to distributed measurement in traditional detection methods, a water temperature field detection system based on a fiber Bragg grating string was designed. In this system, six fiber Bragg gratings with different center wavelengths are connected in series on a single fiber optic cable based on wavelength division multiplexing technology. The fiber Bragg grating string is encapsulated in stainless steel tube and vertically fixed in the measured water body of the fish pond. The space division multiplexing technology is employed to collect information from multiple fiber Bragg grating strings. Water temperature measurement experiments were conducted in the summer pond environment. The experimental results show that the daily variation curve of temperature in each water layer of the fish pond is relatively smooth and approximates a cosine function with a 24-hour period. In summer, the daily average water temperature in the pond is no more than 1°C higher than the average air temperature. The difference between the maximum and the minimum water temperature is approximately 2°C. During the daytime, the temperature gradually decreases from the surface to the deeper water layers, whereas at night, the temperature variation among the water layers is minimal. As depth increases, the amplitude of the water temperature curve oscillations gradually decreases, exhibiting exponential decay. However, the peak time gradually lags behind. There is a correlation between the temperatures of the water layers in the fish pond, and the smaller the distance between the water layers, the stronger the correlation. The experimental results obtained in this study are highly significant for real-time services in aquatic planting and aquaculture. Additionally, this measurement method can provide valuable reference and guidance for measuring temperature fields in other fluids.
为解决传统检测方法中检测效率低且无法适应分布式测量的问题，设计了一种基于光纤布拉格光栅串的水温场检测系统。在该系统中，基于波分复用技术，将六个中心波长不同的光纤布拉格光栅串联在一根单芯光缆上。光纤布拉格光栅串封装在不锈钢管中，并垂直固定在鱼塘的被测水体中。采用空分复用技术从多个光纤布拉格光栅串采集信息。在夏季池塘环境中进行了水温测量实验。实验结果表明，鱼塘各水层温度的日变化曲线相对平滑，近似于周期为24小时的余弦函数。夏季，池塘日平均水温比平均气温高不超过1℃。最高水温与最低水温之差约为2℃。白天，温度从水面到较深的水层逐渐降低，而夜间水层间的温度变化最小。随着深度增加，水温曲线振荡幅度逐渐减小，呈指数衰减。然而，峰值时间逐渐滞后。鱼塘各水层温度之间存在相关性，水层间距离越小，相关性越强。本研究获得的实验结果对水产种植和养殖的实时服务具有重要意义。此外，这种测量方法可为测量其他流体中的温度场提供有价值的参考和指导。
