 
                  Specs at a glance
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                              Measuring range0 to 20 mg/l 
 0 to 200 %SAT
 0 to 400 hPa
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                              Process temperature-5 to 60 °C 
 (20 to 140 °F)
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                              Process pressureMax. 10 bar abs 
 (Max. 145 psi)
Field of application
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.
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 
Videos
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        Standard products 
- Reliable, robust and low-maintenance
Technical excellence
Simplicity
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        Specialized products 
- Designed for demanding applications
Technical excellence
Simplicity
Variable
| FLEX selections | Technical excellence | Simplicity | 
|---|---|---|
| 
 Fundamental selection Meet your basic measurement needs | Technical excellence | Simplicity | 
| 
 Lean selection Handle your core processes easily | Technical excellence | Simplicity | 
| 
 Extended selection Optimize your processes with innovative technologies | Technical excellence | Simplicity | 
| 
 Xpert selection Master your most challenging applications | Technical excellence | Simplicity Variable | 
Extended selection
- 
        High-end products 
- Highly functional and convenient
Technical excellence
Simplicity
 
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                                                    Technical Information (TI)
 Oxymax COS61D/COS61English version - 01/2022 Optical sensor for measuring dissolved oxygen EN 05/01/202219/02/202117/07/201821/08/201207/06/2010Language: English Version: 05/01/2022 File size: 1.9 MB File name: TI00387CEN_1621-00.pdf 
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                                                    Operating Instruction (BA)
 BA Oxymax COS61DEnglish version - 06/2025 Sensor for measuring dissolved oxygen with Memosens protocol EN 03/06/202513/12/202119/03/202117/07/201830/09/2016Language: English Version: 03/06/2025 File size: 2.8 MB File name: BA00460CEN_1824-00.pdf 
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                                                            Technical Information (TI)
 Oxymax COS61D/COS61Optical sensor for measuring dissolved oxygen EN 05/01/202219/02/202117/07/201821/08/201207/06/2010Language: English Version: 05/01/2022 File size: 1.9 MB File name: TI00387CEN_1621-00.pdf 
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                                                            Operating Instruction (BA)
 BA Oxymax COS61DSensor for measuring dissolved oxygen 
 with Memosens protocolEN 03/06/202513/12/202119/03/202117/07/201830/09/2016Language: English Version: 03/06/2025 File size: 2.8 MB File name: BA00460CEN_1824-00.pdf 
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                                                            Operating Instruction (BA)
 Operating Instructions - Compressed air cleaning unit - 115VACOperating Instructions - Compressed air cleaning unit - 115VAC Language: English Version: 29/01/2013 File size: 1.8 MB File name: BA00498CEN_0113.pdf 
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                                                            Short Instruction (KA)
 KA Oxymax COS61DOptical sensor for measuring dissolved oxygen 
 With Memosens protocolEN 04/06/202501/07/202119/03/202117/07/201830/09/2016Language: English Version: 04/06/2025 File size: 1.7 MB File name: KA01133CEN_0624-00.pdf 
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                                                            Installation Instructions (EA)
 EA Kit for Oxymax COS61/COS61DFor maintenance of oxygen sensors COS61 and COS61D EN 04/03/202518/05/2022Language: English Version: 04/03/2025 File size: 1.1 MB File name: EA01425CEN_0225-00.pdf 
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                                                            Special Documentation (SD)
 SD COV61Maintenance Kit for COS61 and COS61D Language: English Version: 13/03/2025 File size: 287.7 KB File name: SD03389CEN_0125-00.pdf 
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                                                            Fields of Activities (FA)
 Sensors, transmitters, compact devices and assembliesExperts in Liquid Analysis Language: English Version: 24/09/2024 File size: 4.2 MB File name: FA00007CEN_Analyse_21.24_LowRes.pdf 
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                                                            Fields of Activities (FA)
 Kompetenz in der FlüssigkeitsanalyseVom Sensor bis zur schlüsselfertigen Komplettlösung Language: German Version: 21/09/2022 File size: 1.3 MB File name: FA01018CDE_0422_Analyse_Portfolio_lowres.pdf 
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                                                            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Language: Japanese Version: 30/06/2025 File size: 4.6 MB File name: FA01018CJA_0422_Analysis_Portfolio_lowres.pdf 
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                                                            Fields of Activities (FA)
 Sensoren, Messumformer, Kompaktgeräte and ArmaturenKompetenz in der Flüssigkeitsanalyse Language: German Version: 24/09/2024 File size: 4.1 MB File name: FA00007CDE_Analyse_21.24_LowRes.pdf 
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