Oxygen Sensors & Transmitters

Oxygen Sensors & Transmitters

Oxygen measurement systems provide continuous monitoring of dissolved oxygen (DO) in liquids and, in some configurations, oxygen in gas streams. Sensors paired with transmitters convert oxygen-dependent electrochemical or optical signals into stable process values with temperature and pressure considerations as required. DO is one of the most influential variables in biological treatment, fermentation, and corrosion-related water chemistry.

The key benefit is control of oxygen transfer and consumption, which directly impacts energy use, process stability, and product quality. In aeration processes, accurate DO control can significantly reduce blower energy while preventing under-aeration that leads to poor treatment performance. In sensitive water/steam cycles or oxygen-sensitive processes, low-level oxygen monitoring supports corrosion prevention and product protection.

Two common DO technologies are amperometric (Clark-type) and optical (luminescent) sensing. Amperometric sensors provide proven performance but may require electrolyte management and membrane replacement. Optical sensors reduce routine maintenance by eliminating electrolyte handling and are well suited to variable flow or intermittent aeration, with stable long-term drift characteristics in many applications.

Transmitters typically provide compensation, diagnostics, and communications for integration into control systems. Practical installation focuses on representative location, minimizing bubble interference, ensuring adequate mixing, and selecting assemblies that support cleaning in fouling-prone services. Automated cleaning (air blast, mechanical wipe, or chemical cleaning protocols) can be critical in wastewater and high-biofouling environments.

Typical applications include aeration basin control, nitrification/denitrification optimization, activated sludge process monitoring, aquaculture, surface water studies, and fermentation/bioreactor control. Oxygen monitoring is also applied in boiler feedwater and other utility systems where trace oxygen contributes to corrosion risk and scavenger dosing strategy. With the right technology selection and installation discipline, oxygen measurement becomes a high-leverage signal for both performance and operating cost.

Instrumentation and Controls., an exclusive authorized representative of sales and service for Endress+Hauser.