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Digital oxygen sensor Oxymax COS61D

Memosens optical oxygen sensor for water, wastewater and utilities

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Digital oxygen sensor Oxymax COS61D

Memosens optical oxygen sensor for water, wastewater and utilities

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Benefits

  • Minimum maintenance, maximum availability
  • Fast, drift-free measurement for precise aeration control and process monitoring
  • Long-term stability for increased process safety
  • Outstanding performance in all aeration processes (SBR, Anamox, etc.)
  • Chemical-free: no electrolyte handling

Integrated technologies

Memosens technology
Liquiline: cutting-edge transmitter platform
FLEXible answers to individual needs
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Digital oxygen sensor Oxymax COS61D

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Xpert selection Master your most challenging applications
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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.

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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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Technology
Memosens technology

Memosens 2.0: Cutting-edge sensor technology reloaded

Make life easier, increase process safety and stay connected with Memosens 2.0 digital technology.

Technology

Liquiline: cutting-edge transmitter platform

By choosing the Liquiline platform, you’re effectively choosing to spend less money on stock holding, save installation time and gain operational safety!

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Product information

Oxymax COS61D is an optical dissolved oxygen sensor with long-term stable fluorescence layer.
Digital optical oxygen sensor
Specifications
Measuring / Application task Oxygen
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Description

Oxymax COS61D is a high-performance, digital oxygen sensor that offers fast, accurate and drift-free measurement. It supports your process with low maintenance, high availability and easy handling. The sensor's long-term stable fluorescence layer is exclusively oxygen-selective (interference-free), ensuring consistently reliable measurement. Thanks to Memosens digital technology, the Oxymax COS61D combines maximum process and data integrity, and facilitates simple lab calibration.

Field of application

Oxymax COS61D 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
  • Minimum maintenance, maximum availability
  • Fast, drift-free measurement for precise aeration control and process monitoring
  • Long-term stability for increased process safety
  • Outstanding performance in all aeration processes (SBR, Anamox, etc.)
  • Chemical-free: no electrolyte handling
Downloads
Most downloaded
Technical Information (TI)
Oxymax COS61D/COS61 Optical sensor for measuring dissolved oxygen
English version - 01/2022
Download
Operating Instruction (BA)
BA Oxymax COS61D Sensor for measuring dissolved oxygen
with Memosens protocol
English version - 06/2025
Download
Operating Instruction (BA)
Operating Instructions - Compressed air cleaning unit - 115VAC Operating Instructions - Compressed air cleaning unit - 115VAC
English version - 01/2013
Download
The CAD Drawings will be available after the configuration.
All downloads
61 Downloads
Technical Information (TI)
Most downloaded
Oxymax COS61D/COS61 Optical sensor for measuring dissolved oxygen
English version - 01/2022
Download
Operating Instruction (BA)
Most downloaded
BA Oxymax COS61D Sensor for measuring dissolved oxygen
with Memosens protocol
English version - 06/2025
Download
Operating Instruction (BA)
Operating Instructions - Compressed air cleaning unit - 115VAC Operating Instructions - Compressed air cleaning unit - 115VAC
English version - 01/2013
Download
Short Instruction (KA)
KA Oxymax COS61D Optical sensor for measuring dissolved oxygen
With Memosens protocol
English version - 06/2025
Download
Installation Instructions (EA)
EA Kits COS61/COS61D Electronics Spare Parts Kits COS61/COS61D Electronics
English version - 01/2026
Download
Installation Instructions (EA)
EA Kit for Oxymax COS61/COS61D For maintenance of oxygen sensors COS61 and COS61D
English version - 03/2025
Download
Ex Safety Instruction (XA)
XA Memosens oxygen sensors NI Class I Div 2 Groups A, B, C, D
Safety instructions for electrical apparatus in explosion-hazardous areas
English version - 07/2026
Download
Special Documentation (SD)
SD COV61 Maintenance Kit for COS61 and COS61D
English version - 03/2025
Download
Fields of Activities (FA)
Sensors, transmitters, compact devices and assemblies Experts in Liquid Analysis
English version - 02/2026
Download
Fields of Activities (FA)
Esperti nell’analisi dei liquidi Dai sensori singoli a soluzioni
complete “chiavi in mano”
Italian version - 01/2017
Download
Fields of Activities (FA)
Kompetenz in der Flüssigkeitsanalyse Vom Sensor bis zur schlüsselfertigen Komplettlösung
German version - 09/2022
Download
Fields of Activities (FA)
水質分析の専門知識 センサからすべてを備えた
ターンキーソリューションまで
Japanese version - 06/2025
Download
Fields of Activities (FA)
Catálogo Portfolio Analítica Desde sensores hasta soluciones completas
Spanish version - 01/2017
Download
Fields of Activities (FA)
Sıvı analizinde uzmanlık Sensörlerden komple anahtar teslim çözümlere
Turkish version - 11/2023
Download
Fields of Activities (FA)
Expertise in liquid analysis From sensors to complete turnkey solutions
English version - 09/2022
Download
Fields of Activities (FA)
Jistota v analýze kapalin Od senzorů po kompletní dodávku na klíč
Czech version - 01/2017
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
Competence Brochure (CP)
良質な水のために 上水道、配水網、地表水、工業プラント向けの斬新なアイデア
Japanese version - 05/2025
Download
Competence Brochure (CP)
Aus Freude an gutem Wasser Frische Ideen für Wasserwerke, Verteilernetze, Oberflächenwasser und
Industrieanlagen
German version - 07/2023
Download
Competence Brochure (CP)
Making sure your WWTP runs and runs and runs Efficient and effective wastewater treatment
English version - 08/2018
Download
Competence Brochure (CP)
For the love of quality water Fresh ideas for waterworks, distribution networks, surface waters and
industrial plants.
English version - 07/2023
Download
Case Study (CS)
Überwachung der Wasserqualität in Fischzuchtbecken Digitalisierung der Fischzucht in der Petite Camargue Alsacienne
German version - 09/2021
Download

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Spare parts and accessories

further parts
further parts

COV61 maintenance kits COS61/COS61x

further parts
further parts
Order code COV61-
Measuring chamber
Measuring chamber

Sensor cap, COS61,COS61D, 1 piece

Measuring chamber
Measuring chamber
Order code 51518598
Drawing number 3
Sealing
Sealing

Sealing set,SensorCOS61,COS61D2pieces

Sealing
Sealing
Order code 51518597
Drawing number 2
further parts
further parts

Kit COSxx Protection cage Standard

further parts
further parts
Order code 71495128
Spare parts and accessories
Oxymax COS61D is an optical dissolved oxygen sensor with long-term stable fluorescence layer.
Digital optical oxygen sensor

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Oxymax COS61D is an optical dissolved oxygen sensor with long-term stable fluorescence layer.
Digital optical oxygen sensor
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Spare parts and accessories

further parts
further parts

COV61 maintenance kits COS61/COS61x

further parts
further parts
Order code COV61-
Measuring chamber
Measuring chamber

Sensor cap, COS61,COS61D, 1 piece

Measuring chamber
Measuring chamber
Order code 51518598
Drawing number 3
Sealing
Sealing

Sealing set,SensorCOS61,COS61D2pieces

Sealing
Sealing
Order code 51518597
Drawing number 2
further parts
further parts

Kit COSxx Protection cage Standard

further parts
further parts
Order code 71495128
Spare parts and accessories

Selection of compatible products

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