高精度氟离子实时检测系统的设计与实现

Design and Implementation of a High Precision Real-time Detection System for Fluoride Ion

针对现有氟离子检测仪器在检测过程中,电极容易受到外界温度变化的影响,导致实际检测结果精度低的情况。通过实验总结出温度变化对氟离子选择性电极的工作曲线的影响,进而提出温度补偿方法,最终设计并实现了全自动高精度氟离子实时检测仪器。经过实际现场测试对比水样所在地的水质监测站的实验结果表明,该仪器的氟离子浓度检测限可以达到0.02 mg/L,该仪器检测的结果对高浓度水样相对误差在1%以内,对低浓度水样相对误差在3.5%以内。系统具有检测精度高、试剂用量少、实时性好和可靠性高等特点。

During the detection process of existing fluoride ion, electrodes are always affected by external temperature change, which leads to the low precision of results in actual test. This paper summarizes the effect of temperature change on the working curve of fluoride ion selective electrode based on lots of experiments, and then proposes temperature compensation method. Finally, a high-precision instrument for automatically real-time detecting fluoride ion is designed and realized. Experimental results from comparing with the water quality monitoring stations show that the instrument＇ s limit for detection can reach 0.02 mg/L; the relative errors less than 1% when instrument detects water sample with high fluoride ion concentration, and less than 3.5 % when detects low. This system has the characteristics of high precision, less reagent dosage, good real-time performance and high reliability.