Developmentof a Water Quality Analyser Suitable

forUnattended Use in Rivers and Streams

ReportNo WSAA 55


May 1993




Theaims of this project were to develop a rugged, reliable and cost effectivewater quality analyser capable of measuring a number of important water qualitydeterminands automatically, in the field. An integrated system of physicalsensors, electrochemical (ion selective electrodes) sensors, and aspectrochemical sensor capable of measuring turbidity, temperature, water depth,conductivity, and nitrate, chloride and reactive phosphate concentrations wasrequired to achieve this.


Theanalyser was designed with three components. The SUBMERSIBLE unit was locatedin the river and undertook all measurements in-situ. Chemical sensors werecalibrated before each measurement using reference solutions. The CONTROLLERcommunicated with the SUBMERSIBLE to initiate a sampling regime and receivedthe measured data. The COMMUNICATIONS system received data from the CONTROLLERand relayed it the laboratory via ARGOS satellite.


Thedevelopment took place in four phases. Each phase involved significantimprovements to the capabilities of the equipment from the preceding phase andincluded extensive field testing at Houlgrave Weir, on the Onkaparinga River inSouth Australia. All components of the system functioned well and culminated inthe collection of more than 100 days of data.


Theanalyser developed through this project can automatically and reliably measurea variety of important water quality determinands automatically in the field,and transmit the data to the laboratory via satellite for assessment. It isrecommended that real-time monitoring be seen as an important but complementarytechnological advancement to more traditional monitoring procedures, and thatfurther development of the analyser be carried out to improve the measurementof some determinands, particularly conductivity and turbidity, along withextensive field testing.


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