基于位置敏感器件的光学法盐度检测技术研究

盐水浓度的变化会引起其对光的折射率的变化 ,对于固定的倾斜入射光线 ,折射率的变化会导致出射光线发生偏移 ,利用位置敏感器件 (PSD)检测光线偏移量的大小 ,便可以得到待测盐水的浓度。基于差动折射率测量原理 ,引入了一个装有蒸馏水的参考水槽 ,从而有效地减小了温度漂移对盐度测量带来的影响。初步的实验结果表明了方法的正确性 ,盐度测量的分辨力可达 0 .0 12‰ ,重复性精度好于± 0 .3‰。对测量数据做了详细的论述 ,并对影响测量精度的一些主要因素进行了细致的分析。结果表明 ,该方法的温度漂移和光源强度变化对测量结果的影响很小。

Salinity Measurement Based on Position Sensitive Detector and Optical Technology

The developed salinity measurement setup exploits beam deviation caused by refraction due to the salinity of measured water at the receiving end face of a measurement cell. Based on a differential refractometry, a reference water cell filled with distilled water to reduce influence of temperature drift effectively is partitioned by an oblique optical-transmission plate from a horizontal rectangular water tank, which, as a measurement element, is filled with measured salt water. Beam deviation caused by salinity change is detected by a position sensitive detector. Experimental results indicate the feasibility of the developed system with a measurement resolution of 0.012‰ and repeatability error less than ±0.3‰. Errors which will affect the measurement performance are discussed and analyzed in detail. The results indicate that temperature and light power drifts have little influence on the measurement accuracy.