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Dissolved oxygen sensor Oxymax COS41

Amperometric oxygen sensor for water, wastewater and utilities

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Dissolved oxygen sensor Oxymax COS41

Amperometric oxygen sensor for water, wastewater and utilities

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Benefits

  • High measurement accuracy
  • Long maintenance intervals
  • Minimum calibration effort thanks to simple air calibration
Manufacturer's warranty

Engineered for confidence

Our instruments are designed for long‑lasting performance, precise measurement, and dependable operation in demanding industrial environments. Each product includes a standard manufacturer’s warranty that reflects our commitment to quality and to the trust you place in our solutions.

Should a warranty case occur, the device will be assessed and the applicable remedy will be provided in line with the warranty terms – helping ensure a reliable and efficient resolution and supporting continued operation of your measurement point.

Request for extended warranty

If you require extended warranty coverage, simply contact your local Endress+Hauser representative. Our experts will advise you on the available options to match your application and risk profile, helping you protect your investment, reduce unexpected repair costs, and ensure reliable long‑term operation beyond the manufacturer's warranty period.

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Warranty terms apply

The manufacturer's warranty and extended warranty are subject to specific conditions. For full details, please refer to the locally applicable General Terms and Conditions (GTC), which can be found on the respective country page of our website.

Services by your side

Right‑first‑time commissioning, worldwide

Endress+Hauser’s qualified service engineers ensure your measurement devices are commissioned right the first time, delivering application‑aligned accuracy, regulatory compliance, and operational confidence from startup onwards, anywhere in the world.

Remote support you can trust wherever you operate

With Endress+Hauser Smart Support, you benefit from faster issue resolution, higher uptime, reliable global expertise across the entire product lifecycle – and lasting peace of mind.

Committed to long‑term, sustainable performance

With deep field expertise, harmonized processes, and continuous monitoring, we accompany you with comprehensive service offerings – from initial start‑up through instrumentation maintenance to process optimization – as a true lifetime partner delivering improved outcomes.

For additional information, please contact your local Endress+Hauser representative.

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Product information

Oxymax COS41 is a reliable oxygen sensor for all kinds of water & wastewater applications.
Amperometric oxygen sensor
Specifications
Measuring / Application task Oxygen
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Description

Oxymax COS41 is a reliable and accurate oxygen sensor for all kinds of water & wastewater applications. Designed for reduced maintenance and a long operating life, the sensor offers real value for money.

Field of application

Oxymax COS41 measures the dissolved oxygen concentration in:

  • Wastewater treatment plants: - O2 control in the aeration basin - Process water treatment and monitoring
  • Water works: - Status monitoring of drinking water (oxygen enrichment, corrosion protection, etc.) - Water quality monitoring in rivers, lakes or seas
  • Utilities of all industries: - O2 control in the biological treatment - Process water treatment and monitoring
  • Fish farming: - O2 control for optimum growth conditions
Benefits
  • High measurement accuracy
  • Long maintenance intervals
  • Minimum calibration effort thanks to simple air calibration
Predecessors
COS4, COS4HD
Downloads
Most downloaded
Operating Instruction (BA)
Operating Instructions Oxymax W COS41 Sensor for Measuring Dissolved Oxygen
English version - 04/2004
Download
Technical Information (TI)
Technical Information Oxymax W COS41 Amperometric oxygen sensor
English version - 03/2007
Download
Short Instruction (KA)
Brief Operating Instructions Oxymax W COS41 Amperometric oxygen sensor
English version - 06/2005
Download
The CAD Drawings will be available after the configuration.
All downloads
171 Downloads
Technical Information (TI)
Most downloaded
Technical Information Oxymax W COS41 Amperometric oxygen sensor
English version - 03/2007
Download
Operating Instruction (BA)
Most downloaded
Operating Instructions Oxymax W COS41 Sensor for Measuring Dissolved Oxygen
English version - 04/2004
Download
Short Instruction (KA)
Brief Operating Instructions Oxymax W COS41 Amperometric oxygen sensor
English version - 06/2005
Download
Installation Instructions (EA)
EA Kit COS41/COS51D/E for maintenance of the Oxymax W COS41/COS51D and Memosens COS51E oxygen
sensors
English version - 05/2023
Download
Special Documentation (SD)
SD COV45 Maintenance Kit for COS41,
COS51D and COS51E
English version - 10/2024
Download
Fields of Activities (FA)
Sensors, transmitters, compact devices and assemblies Experts in Liquid Analysis
English version - 02/2026
Download
Fields of Activities (FA)
Sensoren, Messumformer, Kompaktgeräte and Armaturen Kompetenz in der Flüssigkeitsanalyse
German version - 02/2026
Download
Fields of Activities (FA)
Sensori, trasmettitori, dispositivi compatti e armature Sensori, trasmettitori,
dispositivi compatti e armature
Esperti in materia di analisi dei
liquidi
Italian version - 06/2026
Download
Fields of Activities (FA)
Endress+Hauser 水質分析計ファミリ ラインナップと事例
Japanese version - 03/2017
Download
Electrolytes
COV45-41TNx_51Txx (Canada (French)) Electrolyte for COS41/COS51D/E
French version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Finland) Electrolyte for COS41/COS51D/E
Finnish version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Italy) Electrolyte for COS41/COS51D/E
Italian version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Switzerland (Italian)) Electrolyte for COS41/COS51D/E
Italian version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (France) Electrolyte for COS41/COS51D/E
French version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Ireland) Electrolyte for COS41/COS51D/E
English version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (New Zealand) Electrolyte for COS41/COS51D/E
English version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Czech Republic) Electrolyte for COS41/COS51D/E
Czech version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (United Arab Emirates) Electrolyte for COS41/COS51D/E
01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Ukraine) Electrolyte for COS41/COS51D/E
01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Norway) Electrolyte for COS41/COS51D/E
Norwegian version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Poland) Electrolyte for COS41/COS51D/E
Polish version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Netherlands) Electrolyte for COS41/COS51D/E
Dutch version - 01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Lithuania) Electrolyte for COS41/COS51D/E
01/2025
Download
Electrolytes
COV45-41TNx_51Txx (Belgium (Dutch)) Electrolyte for COS41/COS51D/E
Dutch version - 01/2025
Download

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Selection of compatible products

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Spare parts and accessories

further parts
further parts

COV45 maintenance kits COS41/COS51x

further parts
further parts
Order code COV45-
further parts
further parts

Kit COSxx Protection cage 8,5 mm holes

further parts
further parts
Order code 71495126
further parts
further parts

Kit COSxx Protection cage Standard

further parts
further parts
Order code 71495128
further parts
further parts

Kit COSxx Protection cage Fish farming

further parts
further parts
Order code 71495130
Spare parts and accessories
Oxymax COS41 is a reliable oxygen sensor for all kinds of water & wastewater applications.
Amperometric oxygen sensor

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Oxymax COS41 is a reliable oxygen sensor for all kinds of water & wastewater applications.
Amperometric oxygen sensor
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Spare parts and accessories

further parts
further parts

COV45 maintenance kits COS41/COS51x

further parts
further parts
Order code COV45-
further parts
further parts

Kit COSxx Protection cage 8,5 mm holes

further parts
further parts
Order code 71495126
further parts
further parts

Kit COSxx Protection cage Standard

further parts
further parts
Order code 71495128
further parts
further parts

Kit COSxx Protection cage Fish farming

further parts
further parts
Order code 71495130
Spare parts and accessories

Selection of compatible products

/