For couple of months I'm at Shanghai, working with DFRobot, a robotics and open source hardware provider company, to develop an open source automatic water quality monitoring device that could be used for Pearl River monitoring.
Background in environmental investigation NGO, my knowledge on electronic development is very limited. Hopefully this document could help people like me to easily understand and replicate such a tool.
KnowFlow is the name of this water quality monitoring device, based on Arduino Uno. It can automatically monitor 5 parameters of water: pH, Temperature, Dissolved Oxygen, Electronic Conductivity, ORP.
Currently, KnowFlow is powered by a 7.4V lipo battery, the data is stored in a SD card. The field test will be described in a separate research note.
DFRobot produces all the electronic components except for DO, which is produced by Atlas Scientific (btw, all the DFRobot's products are open source), most of the materials I listed are made by them.