全自动PH值测量系统设计说明

摘 要本论文设计用电化学原理和 MSC–51 单片机技术对各种溶液中氢离子浓度进行测定。本论文详细论述了 PH 测量仪的设计，包括氢离子浓度的测量，标定方法，温度检测装置，测量电路和软件系统设计。PH 测量仪用三电极检测系统，参比电极和指示电极对溶液中氢离子检测。三电极系统有良好地抗干扰能力。输入电路采纳高阻差分电路，传感器的设计可以减少溶液中其他离子的干扰。仪器以 MSC–51 单片机系统，可以完成仪器的自动校准，温度补偿等功能。采纳人机对话可以实现自动测量，存储，显示等功能。在实际的测量系统中，能斯特方程相应的实际曲线往往偏离理想曲线，所以中有知道实际的曲线才能用测量系统中的电极。故采纳两点标定法，计算出实际的斜率和温度，才能正确测量。关键词：三电极检测，高阻，温度补偿 AbstractOn the basis of electrochemical principal and Instrument circuit system to MCS–51 microcontroller core, this system can measure activity in solution .The paper details the design of the PH instrument. Including measuring principle, the calibration way, the design of temperature transducer, measuring circuit software.The ph tester is equipped with three–electrode measurement system. The concentration of hydrogen was determined by the appropriate reference electrode and indicator electrode measurement .the system can greatly reduce the impact of outside interference. The unique sensor design can reduce the reference electrode and ionic interference. The MCS–51 microcontroller core can automatically adjust the scope, automatic temperature compensation etc. the use of man-machine dialogue can enable automatic measurement, storage, display data functions. In the actual measurement system, the Nernst equation corresponding to the actual curve often deviate the ideal curve, with the use of two-point calibration method, we can actually calculate the actual slope and temperature.Key words: three–electrode measurement system, high resistence，the tempe...