Research And Design Of Water Quality Conductivity Online Monitoring System

With the continuous improvement of today’s scientific and technological level and comprehensive national strength,a serious problem with rapid economic growth is environmental pollution,and water pollution is one of the most urgent problems in environmental pollution.Because it is not only about people’s physical health,but also about the development of the entire human future.Water quality monitoring is important measure for water pollution and water security,and the detection of water quality conductivity is particularly important.The traditional monitoring system of water quality conductivity is large and complicated,it is also expensive to establish monitoring stations in the river basin.The laboratory testing system requires that the tested samples should be sampled and brought back to the laboratory for testing,which will greatly reduce the detection accuracy.And the portable detector is only able to detect water quality conductivity at a specific time,so it can’t satisfy the needs of real-time monitoring.Therefore,this paper designs a rapid,portable,low-cost and real-time online monitoring system for water quality conductivity monitoring,and further builds the real-time online monitoring network of water quality conductivity based on ZigBee communication protocol.At first,this paper puts forward the overall design scheme of the on-line monitoring system of water quality conductivity,which is divided into two parts of hardware and software.The hardware part mainly includes the hardware designs of the sensor nodes,the coordinators and the hardware circuits of routers;The software part mainly introduces the program designs for the single-chip microcomputer,the network and the upper computer.The hardware design of the sensor network nodes is the key point in the hardware part,and it mainly consists of the designs of the signal generating circuit,the filter circuit,the controlling circuit,the ZigBee modular circuit,and the detecting circuit for the conductivity and the temperature.Finally,the performance of the circuits were tested by means of oscilloscope and other tools.And the experiments for detecting conductivity and experiments of ZigBee’s network and data transmission were designed according to the corresponding national standards.The experiments’ results show that the circuits’ performance of the sensor network nodes meets the design requirements,the relative error of the conductivity detection is within 1%and the network’s average drop rate is 0.260%.Therefore,the designed monitoring system meets the demand of monitoring river online in real time and it can also add sensor nodes to increase monitoring area based on demands.