秦夕淳,袁 琦,周宝宣
(海南大学机电工程学院,海南 海口 570228)
摘要:设计了一套基于离子选择性电极与单片机技术的水产养殖环境因子检测仪,用于快速检测水产养殖中影响水质的硝酸根(NO3-)、铵根(NH4+)等离子。基于能斯特方程与最小二乘法对电极响应电势与相应离子浓度的一元线性回归模型进行了研究,建立了两者之间的函数关系。便携式检测仪采用离子选择性电极作为信号采集器,通过单片机系统和串行模数转换模块实现了较高精度、低成本的数据采集,并通过液晶显示模块实现数据的实时显示。通过相关试验,得到了NO3-选择电极响应电位E与离子浓度C的线性回归方程;运用标准浓度KNO3溶液对回归模型进行了验证,线性回归模型的计算值与实际值间的相对误差在1.4%~5.6%。对NH4+检测结果表明,检测仪可以满足一般精度要求的检测,可用于水产养殖中NO3-和NH4+等因子的初步检测分析。
关键词:离子选择性电极;水产养殖;环境因子;最小二乘法
Research on detector of aquaculture environmental factors based on ion selective electrode
QIN Xichun,YUAN Qi,ZHOU Baoxuan
(College of Mechanical and Electrical Engineering, Hainan University, Haikou 570228,China )
Abstract: Based on ISE and MCU, a detector of aquaculture environmental factors is designed, which can be used for rapid detection of the factors which affecting fishery production, such as NH4+ and NO3-. The linear regression model of the ion selective electrode response potential and target ion concentration was studied based on the Nernst equation and least square method and the function relation was also established. Ion-selective electrodes were used to be signal acquisition. MCU and A/D chip were used to compose data acquisition system. LCD was used for real-time data display. Through the relevant experiments, the linear regression equation of nitrate ion selective electrode response potential E and ion concentration C was obtained. The model was verified through standard concentration of KNO3, and the relative error between calculated value and real vale was 1.4% -5.6%. Used the detector for comparative experiments of ammonia ion detection. The detection results for NH4+ showed that the detector could satisfy requirements of detection at certain accuracy which can be used for preliminary detection and analysis of aquaculture environmental factors.
Key words: ion selective electrode; aquaculture; environmental factors; the least square method