Roundtable Highlights Need for Improved Maintenance of Dissolved Oxygen Sensors  

A roundtable discussion last month with water industry and regulatory experts has agreed that there is a need for improved maintenance of dissolved oxygen sensors to increase the accuracy of dissolved oxygen measurements.
The roundtable, which was hosted in Manchester by specialist electrochemical-sensor manufacturer, Analytical Technology (ATI), was made up of leading industry and regulatory experts. The panel was chaired by Michael Strahand, General Manager of ATI Europe and included Alan Henson from Yorkshire Water, Andy Morse, Richard Bragg and Khaled Gajam from United Utilities, Jorgen Jonsson from The Water Research Centre and Robin Lennox from South West Water.

The panel was invited together to share their views concerning dissolved oxygen sensors for reliable dissolved oxygen measurement. While discussions centred on the use of optical sensors compared to galvanic oxygen sensors for accuracy, there emerged an overall consensus among the panel that the most pressing problem was the difficulty in cleaning both types of sensor resulting in a build up of sludge affecting the accuracy of both instrument types.

Such problems also unearthed an issue of damaged trust between manufacturers of sensors and water companies, as previously some manufacturers had sold sensors as “maintenance free”. Those present at the meeting claimed large amounts of time and resources were being spent each year on cleaning sensors. Panel members asked suppliers of dissolved oxygen sensors present, for more information and guidance on the cleaning of these instruments.

The overarching conclusion of the discussion was that instrument maintenance is more important to users than the technology; the instrument must be properly maintained and regularly cleaned in order to measure dissolved oxygen accurately. It was accepted that electrochemical and optical sensors are both capable of delivering the accuracy and reliability required by water companies if they are kept clean and well maintained. It was suggested that manufacturers include a maintenance warranty and a technological demand was raised for the auto-cleaning functions of dissolved oxygen sensors to include a sensor to detect when it needs cleaning and to sound an alarm.

For further information and a full account of the roundtable discussion please visit www.atiuk.com.