The Rosemount 490A optical dissolved oxygen sensor is ideal for use in wastewater aeration basins and ponds, utilizing the EPA-approved luminescence-quenching method for DO measurement. The low-maintenance sensing cap provides accurate and reliable readings with minimal upkeep.

The sensor accurately measures in both liquid and gas phases without requiring separate calibrations, and provides reliable readings within 90 seconds of transitioning from dry to wet conditions. It features chemical and abrasion resistance, extended sensor and sensor cap life (2 years), and a low-maintenance sensing cap.

With a measurement range of 0-60 mg/L or 0-600% saturation, accuracy of ±0.1 mg/L in the 0-20 mg/L range, and response time under 45 seconds to 90% of final value, the 490A delivers reliable performance. The easy-to-configure Modbus interface ensures seamless integration and setup. The sensor is rated for pressures up to 150 psi and depths to 689ft.