Analysis and Solution on the Correlation between Dissolved Oxygen Sensor and pH Sensor for Water Quality Monitoring

This paper designs a multi parameter real-time water quality on-line monitoring system for aquaculture water. This system achieves the online monitoring among temperature, turbidity, DO (dissolved oxygen), pH and electrical conductivity. The crosstalk, produced by the simultaneous measurement with DO and pH sensors, will affect accuracy and stability of monitoring results. This paper analyzes the source of crosstalk, describes a circuit model of causing crosstalk, and designs an isolated circuit between powers and signals as well. The experimental results show that, the real-time monitoring of DO and pH has the characteristics of speediness, high precision, small error and low noise.