Online Multi-parameter Water Quality Monitoring System

Water quality monitoring as an important part of factory aquaculture is the key forfactory aquaculture to develop towards automation, large-scale, high-yield andhigh-quality. Aiming at improving the lagging method and the low automation level ofour country's factory aquaculture, an online multi-parameter water quality monitoringsystem is developed in this dissertation, which can continuously monitor such waterquality parameters as temperature, pH, dissolved oxygen and salinity on line. The mainresearch results are as follows: Firstly, based on computer network and sensortechnology, an on-line and fully informationized monitoring mode of factory aquacultureis built up, and a two-level monitoring system architecture based distributed controlmode is developed. Secondly, by analyzing the environmental particularity of waterquality monitoring and the relationship between water quality parameters and the growthof fish, reasonable selection for choosing sensors is specified. Thirdly, the lowercomputer system consists of single chip computer AT89S52 and peripheral interfacecircuits that include RAM, ROM, keyboard, liquid crystal display, data acquisition,warning and data communication. The system has strong anti-interference performanceand power failture protection circuit for RAM. Several lower computers are linked to oneupper computer by RS485 bus, thus the monitoring system is composed. Fourthly, amultifunctional and flexible monitoring program for this monitoring system is developedby use of Visual C++ and C51 for upper computer and lower computer respectively. Theprogram includes following blocks: keyboard scanning, displaying, data acquisition, datacommunication, data management, on-line monitoring and parameter setting. Finally,the preliminary test carried on the online multi-parameter water quality monitoringsystem proves the correctness and feasibility of the design, and the research results havepractical applied value in the factory aquaculture.