Anglian Water cuts aeration calibration with ABB dissolved oxygen sensors
ABB's new generation of optical dissolved oxygen sensors deliver improved aeration performance for leading water company
Anglian Water Services Ltd has cut calibration of an aeration control system at its Coningsby Sewage Treatment Works by moving to ABB ADS430 Dissolved Oxygen sensors.
The new solution cuts calibration intervals from three months to two years. It also improves accuracy and is easier to use and read than the previous sensors.
Keith Wilson, Senior ICA Technician for the site, was looking for a solution that would replace the existing ABB galvanic sensors. "Our existing sensors were coming to the end of their lives and we thought we would see what ABB’s latest products had to offer. We also had an issue with galvanic sensors in that they had to be surface mounted in the tank. This caused bouncing which can result in inconsistent readings.
"Galvanic sensors also need frequent calibration.”
Following a training day at an ABB facility, Keith decided to adopt the new ABB ADS430 optical dissolved oxygen sensor, part of the Aztec range of advanced digital sensors.
Comprised of a sensor and multi-channel transmitter, ABB’s optical dissolved oxygen sensor system uses optical measurement technology to give the highest levels of stability and accuracy for dissolved oxygen measurement.
The dissolved oxygen concentration is calculated and relayed to the transmitter. The resulting information is then used to fine-tune dissolved oxygen levels to match the requirements of the process. Unlike other optical dissolved oxygen systems, the sensor can be deployed for extended periods of time without a need for calibration.
Says Keith: "The optical sensors need very little maintenance. The galvanic sensors needed maintenance every three months to check their calibration, whereas the optical sensors require attention only every two years to change the Smart sensing caps.
"It is also easy to use. We can see easily if there is any deterioration in the sensing heads whereas previously we would need dedicated instrumentation technicians to determine sensor health.
"The sensors give us high reliability at low cost and also give us a lot more information on trends.”
Two transmitters each with two sensors were purchased. One is used as a duty system with other kept offline as a spare.
"Since it was installed five months ago we have had no reason to call in ABB for any service issues. The operators find it simple to use and they have had no problems with the system,” says Wilson.
ABB’s Aztec 400 range of advanced digital sensors are designed for monitoring the key parameters in municipal and industrial water and wastewater treatment. Using Rugged Dissolved Oxygen (RDO®) optical technology, they can provide accurate measurement of dissolved oxygen in the most demanding process environments, including high saline applications. The robust construction resists abrasion and photobleaching effects that limit the lifetime of other optical DO sensors.
Featuring ABB's EZLink technology, the sensors offer plug-and-play measurement with ABB's latest digital transmitters to create the easiest-to-use and maintain monitoring systems on the market today.
For more information, visit www.abb.com/measurement, email firstname.lastname@example.org ref. ADS 430 or call 0870 600 6122.
Watch an animation outlining the key features and benefits of the ADS430 dissolved oxygen sensor here.