Water quality – many ways to keep an eye on the water
Water changes all the time. Oxygen, nutrients, algae and particles vary through the day and the seasons, and small changes can be an early sign that something is about to happen. A single sample gives a snapshot – continuous measurement gives the whole film. YSI, Hach, Aanderaa and TriOS each cover their part of this, from field measurements and the lab to permanent monitoring stations in process plants and at sea.
YSI – from field to permanent monitoring
YSI has handheld instruments for field measurements, such as the Pro series for oxygen, conductivity, pH, turbidity and nutrients. For longer deployments there are the EXO sondes, which measure many parameters at once and can stay out for months – from slim sondes for groundwater wells to versions for buoys and drones. IQ SensorNet brings many sensors together in one network, and the lab instruments cover the analyses indoors.
Hach – water in the process and the lab
Hach is closely linked to drinking water, wastewater and industry. Process analysers and sensors continuously monitor ammonium, chlorine, phosphate, organic carbon and turbidity, among others. Controllers such as the SC4500 collect the measurements, flag maintenance needs before something fails and pass data on to PLC and SCADA. There are also spectrophotometers and portable meters for the lab and the field, and Claros, Hach's platform for following instruments and data remotely.
Aanderaa – measurements at sea
Aanderaa specialises in measurements at sea. The sensors measure oxygen, conductivity, temperature, turbidity and currents, among others. The Optode 4531 oxygen sensor is known for very low drift and a sensing foil that can last more than ten years. SeaGuard loggers can combine many sensors in one monitoring station, often as a string through the water column, while SmartGuard is used on land and buoy stations with weather sensors, among others.
TriOS – optics without chemicals
TriOS makes optical sensors that measure without reagents. OPUS uses UV light to measure nitrate, nitrite and organic load, and NICO is a simpler nitrate sensor. There are also photometers for colour and light transmission, fluorometers for oil compounds in drinking water and wastewater, among others, and radiometers for marine research.
From measurement to action
No supplier is best at everything. The right choice depends on what needs to be measured, where and for how long. At Elio we choose the equipment based on the need and connect it to PLC and SCADA. The values can then be shown together with the rest of the plant, raise alerts when something deviates and be stored as history.
For ReWaste, for example, we supplied and integrated water quality measurement from Hach, together with pressure sensors from ifm and flow meters from Siemens, connected to the control system and Ignition SCADA.
Wondering how water quality can be measured and used in your plant? Read more about sensors and instrumentation or contact us.