Emerson introduced the Rosemount? 490A Optical Dissolved Oxygen Sensor

Emerson has announced the release of the Rosemount™ 490A Optical Dissolved Oxygen Sensor, a digital, Modbus-enabled solution designed to improve operational flexibility, streamline installation, and reduce maintenance costs across a wide range of industrial applications. Ideal for use in water and wastewater treatment, biopharmaceutical manufacturing, food and beverage processing, and steam power generation, the sensor delivers dependable, high-performance oxygen measurements in even the most demanding environments.

Traditional dissolved oxygen sensors are often designed for narrow use cases and relatively stable conditions. These legacy devices typically communicate via analog signals and require frequent calibration to maintain accuracy and avoid sensor drift. In contrast, the Rosemount 490A addresses these limitations with digital Modbus RTU communication, allowing seamless integration into modern control systems through its compatible transmitter.

Capable of producing accurate measurements within 90 seconds of transitioning from dry to wet conditions, the sensor can be used in both liquid and gas phases—without requiring separate calibrations. This versatility enables wide-ranging application use and simplifies inventory and deployment strategies.

The Rosemount 490A features EPA-approved luminescence-quenching optical technology, which eliminates the need for electrolyte refills, dramatically reducing maintenance compared to traditional amperometric designs. With a two-year sensing cap lifespan and the ability to calibrate in ambient air, the sensor minimizes operational downtime and total cost of ownership.

Built for rugged environments, the 490A boasts a chemically resistant, IP68-rated housing for long-term reliability in harsh conditions. Its compact form factor and forward and rear-facing 1-inch NPT threaded connections simplify installation and integration into tight or complex system layouts.

Unlike amperometric sensors, the optical technology in the 490A does not consume oxygen or require water flow to maintain measurement accuracy. Optional guard cap accessories offer features such as anti-fouling protection, air blast cleaning, and weighted orientation, enhancing performance across a broad spectrum of applications.

The sensor provides high-precision measurements with an accuracy of ±0.1 mg/L (0–20 mg/L) and ±2% (20–60 mg/L), ensuring reliable monitoring of dissolved oxygen levels. It pairs seamlessly with the Rosemount 1058 digital transmitter, offering multiple output signal formats to ensure compatibility with various host systems.

Source: emerson.com