提高水质溶液pH值测量精确度的研究  

Study on improving accuracy of measuring pH value of water solution

作　　者：欧启标[1] 赵剑川 刘建圻[1] 辛苗[1] 赵静 兰小海[1] OU Qi⁃biao;ZHAO Jian⁃chuang;LIU Jian⁃qi;XIN Miao;ZHAO Jing;LAN Xiao⁃hai(School of Electronics and Communications,Guangdong Mechanical&Electronical College of Technology,Guangzhou 510550,China)

机构地区：[1]广东机电职业技术学院电子与通信学院

出　　处：《电子设计工程》2020年第1期84-88,93,共6页Electronic Design Engineering

基　　金：广东省自然科学基金资助项目(2016A030313734)

摘　　要：基于电位法测pH值的原理,搭建了一个水质溶液的pH值测量硬件系统,在此硬件系统的基础上对如何提高水质溶液的pH值的测量精确度进行了详细的研究。研究发现,采用传统的方法对溶液的pH特性建立响应方程,然后通过该方程测量溶液的pH值时,系统测量精度为0.1 pH;将同一温度下的酸性溶液和碱性溶液分别建立线性响应方程,然后采用卡尔曼滤波算法对探头输出的电压信号进行滤波处理,再将处理后的信号代入响应方程计算溶液的pH值时,系统测量精度≥0.1pH。该研究结果对于设计精度高、稳定好、价格低廉的pH计具有一定的意义。Based on the principle of potentiometric method to measure pH value,a hardware system for measuring the ph value of a water solution is built. On the basis of this hardware system,the measurement precision of how to improve the pH value of water solution is studied in detail. It is found that if the traditional method is used to establish the response equation to the pH characteristics of the solution,and the pH value of the solution is measured by the equation,then the accuracy of the system is0.1 pH;if the linear response equations of acidic solution and alkaline solution are respectively established at the same temperature,and then filtered by Calman filter algorithm on the probe output voltage signal,then the processed signal is taken into the response equation to calculate the pH value of the solution,the measurement accuracy of the system can be ≥0.1 pH. The study brings great significance to the pH Measurers which require high-accuracy design,good stability and low-cost.

关 键 词：PH值 电位法 复合电极 卡尔曼滤波 精确度 

分 类 号：TN7[电子电信—电路与系统]