I’ve been comparing various professional & DIY scientific water sensors for PH, Salinity, Dissolved Solids, Conductivity, etc. and have come up with these options. I just purchased an Atlas-Scientific Conductivity kit. While I’m told from a scientist friend of mine that they’re not accurate enough for published data collection, I’m hoping they’re sensitive enough for our interactive installation needs. Not to mention, they’re alot easier to connect with our micro-controllers such as the Arduino, then the professional models which need a conversion circuit for the incompatible voltages.
http://atlas-scientific.com/product_pages/kits/ec-kit.html
http://atlas-scientific.com/product_pages/kits/ph-kit.html
https://www.atlas-scientific.com/product_pages/kits/do-kit.html
http://www.globalw.com/products/6820.html
http://www.globalw.com/products/WQ-Cond.html
http://www.hach.com/processphsensors?gclid=COnLtsGS9LQCFSXZQgod7mIA3Q
