Oxygen Sensors & Transmitters

Oxygen Sensors & Transmitters

Dissolved oxygen measurement quantifies oxygen available in water or process liquids, typically using optical (luminescent) or amperometric sensing principles. Oxygen sensors are paired with transmitters that handle temperature compensation, signal processing, and outputs to control systems. Many designs support in‑situ installation in pipes, tanks, aeration basins, and reactors, with accessories for cleaning and protective mounting.

The benefit is direct control of aeration and oxygen-dependent reactions. In biological wastewater treatment, oxygen is a major energy cost driver; accurate measurement enables tighter control that reduces power consumption while maintaining treatment performance. In industrial processes, oxygen measurement helps prevent corrosion, control oxidation reactions, and protect product quality where oxygen pickup or depletion is critical.

Applications include aeration basin control in activated sludge, monitoring of aerobic digesters, and optimization of nitrification. In water treatment and distribution, dissolved oxygen can indicate corrosion risk and help evaluate treatment effectiveness. In boiler feedwater and condensate systems, very low oxygen levels are often targeted to minimize corrosion, making high‑resolution measurement and reliable compensation essential. Oxygen measurement is also used in aquaculture and environmental monitoring.

Installation details matter: sensor location should represent the bulk liquid and avoid dead zones, excessive turbulence, or bubble impingement that can bias readings. For optical sensors, window fouling and coatings influence response; for amperometric designs, membrane condition and electrolyte health are important. Automatic cleaning options, protective guards, and periodic verification improve long-term stability, especially in high-fouling wastewater streams.

Operational value increases with diagnostics, trend-based maintenance, and integration into control loops. Transmitters can provide sensor health indicators, calibration reminders, and alarm management for low oxygen or rapid changes. When dissolved oxygen is coordinated with ammonia, nitrate, and ORP signals, aeration control can shift from simple setpoint control to performance-based strategies that improve effluent stability and reduce operating cost.

Forberg Smith, an exclusive authorized representative of sales and service for Endress+Hauser.