基于长周期光纤光栅的海水盐度监测可行性试验研究

FEASIBILITY STUDY ON SEAWATER SALINITY MONITORING WITH LONG-PERIOD GRATING

在气候变暖、海平面上升和人类活动等因素的作用下,海水入侵问题日益突出。盐度的变化是判定海水入侵严重程度的一个重要依据,因此,海水盐度的原位监测显得尤为重要。目前,海水盐度的传统监测方法缺少原位、实时、长距离的功能,而近年来有关长周期光纤光栅(LPG)技术测量液体折射率的研究为海水入侵过程中的盐度监测提供了一个新的视角。本文以海水入侵过程中盐度监测为研究背景,设计了基于LPG技术测量海水盐度可行性试验,并将测量结果与理论值进行了比较,论证了该技术用于海水盐度测量的可行性。试验结果表明:LPG谐振峰中心波长与盐度之间存在较好的线性关系,且测量值与理论值的线性相关程度较高,通过标定可实现对盐度的测量,LPG技术对海水盐度测量具有可行性。研究成果为研发下一代海水入侵LPG原位实时监测技术奠定了基础。

Under the influence of climate warming,sea plane rising and human activities,the problem of seawater intrusion is becoming more and more serious. The change of salinity is an important basis for judging the severity of seawater intrusion. Therefore,it is very important to monitor the seawater intrusion in situ. At present,the traditional monitoring method of seawater salinity lacks in situ,real-time,long-distance function. In recent years,the study of liquid refractive index based on Long-Period Grating（ LPG） technology has provided a new perspective for salinity monitoring during seawater intrusion. Based on the monitoring of salinity change during seawater intrusion,the authors design the feasibility test of LPG technology applicable to salinity measurement of seawater,and compare the measured result with the theoretical value. The experimental results show that there is a good linear relationship between the resonant center wavelength and the salinity of LPG,and the linear correlation between themeasured value and the theoretical value is high. Then the salinity can be measured with calibration. LPG technique is feasible for salinity measurement. The research results lay the foundation for the development of the next generation LPG in situ real-time monitoring technology of seawater intrusion.