A phosphate ion-selective electrode is studied and a data acquisition system is developed.The data acquisition system can dynamically record and display the potential response curve of the measured solutions.The electrode is made with metallic cobalt（as a kind of sensitive material）.According to the experiments

a math model with response potential and pH value of the solution as independent variables and ion concentration as dependent variable is established so as to compensate the measurement values of the electrode.The experimental results show that the established model can fit response process curves very well

and the measurement values of the electrode influenced by the pH value can be compensated by the model.It offers a reference for the development and application of the phosphate ion selective electrode.