Analyse this – how developments in digital sensing technology are offering new possibilities for water quality measurement

Opinion | March 15, 2023

Nikodem Siwek

Global Product Manager,
Continuous Water Analysis

Increasingly stringent regulations uphold the quality of water returned to watercourses globally and protect the supply of freshwater for drinking, for agriculture and for industry. Analytical sensors used for measuring water quality face some of the toughest operating applications and require regular maintenance regimes to ensure continued accuracy.

The rigours of municipal and industrial water treatment applications mean that analytical sensors face constant contact with substances ranging from toxic liquids through to sewage sludge. It is not surprising that regular maintenance and inspection regimes are needed to ensure continued accuracy.

Maintenance for accuracy

Until relatively recently, carrying out these regimes relied on a combination of manufacturer guidelines, established practice and, to some extent, guesswork. Operators could put together a maintenance schedule based on the likely operational lifespan of a device, coupled with the effects of exposure to the medium being measured. What they often couldn’t predict, however, was the impact of any unforeseen variations, either in the performance of the device or the substance it was in contact with.

Furthermore, the effectiveness of the maintenance and inspection routines relied on having the staff available to carry them out. With a growing number of companies increasingly faced with shrinking engineering teams stretched across multiple sites, there has been a risk that these routines are not always carried out to plan or operated as thoroughly as they should be.

In both cases, there is a risk of measurement performance being affected by deteriorating accuracy or complete instrument failure, increasing the potential for a breach of consent levels and potential for penalties being imposed.

^{Advances in digital technology are making it possible to keep instruments and analyzers in good working order even when operating in harsh, arduous or non-ideal conditions.}

Digital sensors delivering efficiency

With the advent of digital sensors, these challenges are being overcome. When coupled with the arrival of next generation digital transmitters, digital sensors are helping to transform water quality analysis, not least by enabling operators to use the data they generate to create smart maintenance routines. This data can include not just the water quality parameter being measured, but also device-level diagnostics, opening new possibilities for assessing performance and pinpointing problems before they can develop.

By using this data on the known performance of the sensors to create tailored maintenance routines, operators can start to manage their maintenance resources more intelligently and effectively, ensuring that engineers are only dispatched to site when necessary. As well as greatly enhancing the reliability of the installation, the availability of this ‘deeper data’ also helps to reduce the cost of operation and maintenance, enabling digital sensors to offer a much lower total cost of ownership than their analogue counterparts.

These savings are also further being enhanced by the use of low-maintenance sensor designs. ABB’s ATS430 digital turbidity and total suspended solids (TSS) sensor, for example, features a fully sealed design, with no O-rings, seals or gaskets to replace, making it a truly service-free device. The sensor is also highly resistant to fouling, with a choice of polished stainless steel or corrosion-resistant titanium sensor bodies, plus the option of an automatic wiper to remove fouling from the sensor face.

Simplified operation

Another important factor is simplicity. With skilled operators being at a premium, there is a need to ensure that devices can be used easily. This includes not just operation, but also setting up, fine-tuning and fault-finding. For this reason, manufacturers such as ourselves, have worked to minimise the complexity of our devices, enabling them to be used by even the least experienced operators. Our latest generation of digital transmitters feature our ‘EZLink’ plug and play technology, which enables them to be quickly and easily connected to one of our digital sensors, with all necessary information and settings automatically uploaded.

Furthermore, because these transmitters use the ABB common operating interface, operators trained on one of our devices can use the same knowledge to program and operate any of our other instruments and analysers with minimum need for further training.

Benefits in every sense

The inherent benefits of digital water quality sensors mean they are well-placed to help organisations to meet the dual drivers of increasingly stringent environmental legislation and the need to maximise profitability through reduced operating costs.