Save energy and cut aeration costs with the new optical DO sensor

Aeration systems typically use more than half the electricity consumed in a wastewater treatment facility. So, when operational decisions are based on incorrect dissolved oxygen readings, they can create significant unnecessary electrical energy costs, as well as impacting treatment effectiveness.

The new ADS420 smart optical Dissolved Oxygen (DO) sensor delivers the essential measurements that help you avoid those costs.

Smart, reliable, accurate
DO measurement made easy

Designed to work the way you want to work, the new ADS420 utilizes the latest generation of drift-free optical measurement technology – minimizing operational costs and removing the need for routine calibration.

Compact, robust, and digitally enabled it features ABB’s EZLink™ technology, allowing for more efficient measurement and simpler deployment.

EPA compliant technology
EPA compliant technology

Using reliable and proven optical dissolved oxygen method which meets EPA approval.

No need for routine calibration
No need for routine calibration

The digital SmartCap is preloaded with calibration coefficients - simply snap on and start measuring.

No need for routine calibration
Simplified measurement

Access essential sensor data, and support through the EZLink Connect app, for added convenience.

Dependable performance you can rely on

Able to withstand the harshest environments

The ADS420’s fast, stable, and accurate measurements are unaffected by pH, sample flow, sulfides, sulfates and other interferences, that can affect traditional membrane-based sensors.

The tough lumiphore coating is resistant to abrasion and fouling. This ensures reliable long-term deployment in the hostile operating conditions, found in many utility and industrial wastewater treatment processes.

Eliminate manual calibration errors

Each SmartCap is supplied pre-calibrated and contains the factory calibration coefficients, serial number, and other diagnostic and manufacturing information within the membrane cap.

When the SmartCap is connected, this information is automatically uploaded to the sensor with no user calibration required and no special codes to enter. Simply snap on the SmartCap and start measuring.

Eliminate manual calibration errors
EZLink makes measurement easy

The ADS420 is designed to be easy to set up and operate. Supplied fully factory-calibrated, it can be operational in minutes with ABB’s EZLink ‘plug and play’ technology.

Using advanced automatic sensor recognition and set-up, EZLink technology enables the ADS420 to quickly match with our digital transmitters, with no wiring, additional set-up, or fine-tuning required. Once operational, all analysis and signal conditioning are performed within the sensor, with the resulting data relayed digitally to the transmitter.

EZLink makes measurement easy
Stable, drift-free measurement

The ADS420 uses the US EPA-approved Rugged Dissolved Oxygen (RDO™)* method. The method uses a membrane embedded with lumiphore molecules. Oxygen molecules in the sample interact with the lumiphore molecules by altering the membranes luminescent state. The shift in light is measured between the membrane and a reference LED to provide an accurate calculation of dissolved oxygen concentration.

* RDO is a trademark of In-Situ.

Stable, drift-free measurement
Fully automated air cleaning

Biological fouling of oxygen membranes can severely affect sensor performance, leading to inaccurate readings and increased energy usage, unless they are regularly cleaned.

In applications where high biofouling is expected, the ADS420 can be used with ABB’s fully user configurable EZClean system. This robust automatic cleaning system periodically releases a powerful jet of air across the membrane surface, removing any biofilm build up.

Fully automated air cleaning

Improve efficiency through smart real-time data analysis and control

Work the way you want to work, by combing the ADS420 with our latest generation of smart digital transmitters and solutions.

  • Measure at multiple locations for enhanced aeration optimization or combine with other parameters for improved regulatory compliance
  • Easy access to data with seamless digital integration into DCS, or securely monitor and control remotely via your web browser
  • Directly connect to your smart device to access essential sensor information and support whenever and wherever you need it.
AWT20 Front Mobile

Mounting configurations

Versatile, compact design for easy mounting and installation

Floating ball

Ensures a constant submersion depth, with varying water levels.


Mount directly onto a pole using the ¾” NPT thread or ABB pole mounting kit.


Chain mount kit for cost-effective open channel installation.


Quick disconnect T-piece for inline pipe mounting.

Take control of your aeration process

ABB’s new ADS420 DO sensor helps you to:

  • Reduce energy consumption
  • Lower your operational costs
  • Improve operational efficiency

Work the way you want to work, with the ADS420.

Contact us to find out more