在一定温度条件下,海水的盐度与其折射率之间存在线性对应的关系,因此通过测量海水折射率可以推算出其 盐度。详细介绍了几种利用光学方法测量液体折射率,从而间接检测海水盐度的技术,主要包括光纤光栅传 感检测法、表面等离子波检测技术和利用几何光路折变计算折射率的检测技术,重点分析了各种方案的传感器 结构、工作原理、影响测量精确度的因素,以及在实际应用中存在的问题,最后对光学技术在海水盐度实 时检测中的可行性进行了展望。

There is a linear corresponding relationship between the refractive index of seawater and the salinity at a certain temperature, so the salinity can be calculated by measuring the seawater’s refractive index indirectly. Several ways to measure the salinity indirectly through the refractive index measurement using optical methods were introduced particularly, including fiber Bragg grating sensor detection, surface plasma wave detection techniques and detection technologies based on geometrical optics method. The salinity sensor structures, measurement precision of every salinity measurement methods were discussed, the factors that affect measurement accuracy were analyzed, as well as the problem in practical applications. Finally, the feasibility of seawater salinity real-time detection by optical technology was prospected.