Design And Implementation Of A Control And Measurement System For Multi-Parameter Water Quality Monitor

Water quality monitoring plays an important role in pollution prevention andenvironmental protection. With the building up of the Three Gorges Dam, the reservoirwater environment security situation have become increasingly severe. The real-timeonline monitoring to major pollution indicators of reservoir water body is veryimportant.This paper relies on the international cooperation project “Three Gorges reservoirarea environmental monitoring microsystem” of the National Department ofTechnology. This paper aims at the online monitoring demand for the seven indicatorsin the reservoir area water environment, which are chromium(Cr), lead(Pb), totalphenol(Tph), chemical oxygen demand(COD), A surfactant(As), ammonia nitrogen(AN)and total phosphorus(Tps). This paper uses a kind of visible light micro-spectrometerwhich is developped independly by the Micro-System Research Center of ChongqingUniversity. Based on the previous research of the mechanical structure design ofmanipulator-type multi-parameter water quality monitor, this paper has studied with ameasurement and control system, to develop a multi-parameter water quality monitorwith functions of data acquisition, data storage,data processing, results analyzing andresults display. The main works of this paper are:①Aiming at the control needs of a large number I/O devices in this system, acontrol circuit scheme based on dual microcontroller system structure is present, hostmicrocontroller to complete the overall control and slave microprocessor to expand I/Oports.The hardware circuit diagram, the printed circuit board (PCB), and the preparationof the corresponding control software have been designed and completed.②In order to achieve the overall control of instrument and mirco-spectrometer’sdata acquisition and processing, the embedded Linux software platform has been builtbased on the embedded hardware platform using S3C2440A processor as ths core.QT/Embedded graphical library has been transplanted. Data collection, data processingand man-machine interface applications are designed and implemented.③To quantitatively measure the concentrations of multiple indicators and toreduce the interference of the background components and impurities, the algorithm isdesigned and implemented based on visible spectrophotometry method andiso-absorption diplo-wavelength method. ④Synthetically using the above technology, a multi-parameter water qualitymonitor prototype machine is assembled, and its functionality, stability and accuracy aretested. The experimental results fully verify the feasibility of the design and research.