Research On On-line Water Quality Monitoring System Based On LabVIEW

The security of water resources is closely related to the social development and has attracted the attention of all sectors of society.Due to the extensive mode of development since China’s reform and opening up,the domestic freshwater resources have been seriously polluted,making the already scarce freshwater resources even more scarce.The protection and management of water resources is imminent.In order to effectively protect and control water resources,we should first conduct effective real-time monitoring of water quality,and then trace back to the source according to the abnormal situation,find and remedy the source of pollution.This paper used the Lab VIEW software platform of virtual instrument technology to study the monitoring system for on-line water quality monitoring.The system provides raw data support for on-line water quality monitoring,the 3D fingerprint based on time,absorbance,and wavelength axis is very important in monitoring the dynamic changes of water quality.Firstly,this paper introduces the current research situations of on-line water quality monitoring system and virtual instrument technology,proposes a solution of online water quality monitoring system based on Lab VIEW.Secondly,the basic principles of on-line water quality monitoring system based on UV-visible light absorption spectrum are analyzed.In addition,the methods of calculation of instrument detection index and measurement of water quality parameters are introduced.On this basis,starting from two aspects of lower computer and PC monitoring software,the function and work flow of on-line water quality monitoring system are designed,and processes by using Lab VIEW to realize the functions of monitoring software are described in detail,which include real-time acquisition and processing of spectral data,conversion of absorbance data,reading and writing of absorbance data,waveform display,measurement of COD content in water samples,and over-limit alarm,etc.Finally,on-line water quality monitoring function and detection performance of system are tested by online monitoring of living water sources and waste water treatment plant’s water sample,the analysis of result shows that the system can meet the expected requirements.The on-line water quality monitoring system based on Lab VIEW studied in this paper has many functions,such as human-computer interaction interface,multiple waveform display modes,intuitive over-limit warning method,historical data playback,and adjustable system parameters,etc.This system meets the design requirements of the project,and has a broad application prospect.