为了实现水中氨氮质量浓度的在线检测, 基于光纤光栅传输理论, 提出了一种利用级联光栅, 双参量同步测量的传感方案, 推导出传感系统的灵敏度矩阵。实验测出了布拉格光纤光栅(FBG)和长周期光纤光栅(LPFG)的温度灵敏度系数、氨氮质量浓度灵敏度系数, 获得了传感系统的灵敏度矩阵。结果表明, 该方案结构简单、易于实施, 为水中氨氮在线检测的研究提供了一种参考方案。

In order to realize the real-time monitoring of the ammonia nitrogen concentration and temperature in the water, we presented an approach of double-parameter simultaneous measurements using a cascaded fiber grating sensor, based on transmission theory of fiber grating. The sensitivity matrix of the sensing system is derived. The temperature sensitivity coefficients and the ammonia nitrogen concentration sensitivity coefficients of the fiber bragg grating(FBG) and long periocl fiber grating(LPFG) are measured, and the sensitivity matrix of the sensing system is obtained. Results indicate that the scheme has a simple structure and is easy to implement, and provides a new feasible reference program for the real-time monitoring of the ammonia nitrogen in the water.