Specs at a glance

Measuring range

0 to 20 mg/l
0 to 200 %SAT
0 to 400 hPa
Process temperature

-5 to 60 °C
(20 to 140 °F)
Process pressure

Max. 10 bar abs
(Max. 145 psi)

See all specifications

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

The concentration of oxygen dissolved in a liquid can be measured using the amperometric or optical measuring principles. This video shows what it is about and how these measuring principles work.

Extended selection

High-end products
Highly functional and convenient

Technical excellence

Simplicity

What is FLEX?

Simple products
Easy to select, install and operate

Technical excellence

Simplicity

What is FLEX?

Standard products
Reliable, robust and low-maintenance

Technical excellence

Simplicity

What is FLEX?

High-end products
Highly functional and convenient

Technical excellence

Simplicity

What is FLEX?

Specialized products
Designed for demanding applications

Technical excellence

Simplicity

Variable

What is FLEX?

FLEX selections	Technical excellence	Simplicity
F L E X Fundamental selection Meet your basic measurement needs	Technical excellence	Simplicity
F L E X Lean selection Handle your core processes easily	Technical excellence	Simplicity
F L E X Extended selection Optimize your processes with innovative technologies	Technical excellence	Simplicity
F L E X Xpert selection Master your most challenging applications	Technical excellence	Simplicity Variable

Learn more about the FLEX selections

Loading alternative products

Success stories

Monitoring water quality in fish farms

Optimal water quality in fish farming with the Endress+Hauser monitoring solution with the latest measurement technology and data management
Read the full story
Toilet flushing with a fresh sea breeze

Using seawater to flush toilets can save a lot of drinking water. To ensure a constant water supply, the sensors used must function reliably to meet the water quality objectives (WQO).
Read the full story
50% less precipitant - 100% reliability and cooperation

IDEA achieved tremendous cost savings through continous monitoring with the CA80PH Analyzer at their site in Wallonia
Read the full story
An automated system for pH measurements at AVR

AVR Waste in Botlek, Rotterdam, processes up to 1.7 million tons of residual waste per year. Discover how they optimized their pH measurement thanks to Endress+Hauser
Read the full story
Automated pH measuring point in wastewater

The Dow plant in Stade relies on Endress+Hauser solutions for pH monitoring in the treatment of production wastewater.
Read the full story

Could also interest you

Related topics
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!
More information
Related topics
Memosens 2.0: Cutting-edge sensor technology reloaded

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

Measuring principle

Optical oxygen measurement
Application

Aeration tank, river monitoring, water treatment, fish farming
Characteristic

Digital, optical measurement of dissolved oxygen based on fluorescence quenching
Measurement possible in still water
Measuring range

0 to 20 mg/l
0 to 200 %SAT
0 to 400 hPa
Measuring principle

Oxygen-sensitive molecules (marker) are integrated in an optical active layer (fluorescence layer). The fluorescence layer surface is in contact with the medium. The sensor optics are directed at the back of the fluorescence layer. The sensor optics transmit green light pulses to the fluorescence layer. The markers respond (fluoresce) with red light pulses. The duration and intensity of the response signals depend directly on the oxygen contents or partial pressure.
Design

Calibration data saved in sensor
High degree of EMC protection
Material

Sensor shaft: stainless steel 1.4435
Membrane cap: POM
Dimension

Diameter: 40 mm (1.57 inch)
Shaft length: 186 mm (7.32 inch)
Process temperature

-5 to 60 °C
(20 to 140 °F)
Process pressure

Max. 10 bar abs
(Max. 145 psi)
Temperature sensor

NTC 30K
Connection

Process connection: G1, NPT 3/4"
Cable connection: fixed cable or TOP68 plug-in-head

Filter

Search spare parts by number in drawing

- Show drawing (PDF)

60 spare parts & accessories

COV61 maintenance kits COS61/COS61x

further parts

Order code

COV61-
Sensor cap, COS61,COS61D, 1 piece

Measuring chamber

Drawing number

Order code

3

51518598
Sealing set,SensorCOS61,COS61D2pieces

Sealing

Drawing number

Order code

2

51518597
Kit COSxx Protection cage Standard

further parts

Order code

71495128
Protectiv.cage for COS31/41/51D/61/71

Housing/housing accessories

Drawing number

Order code

4

50053276
Kit COSxx Protection cage Fish farming

further parts

Order code

71495130
Kit COSxx Protection cage 8,5 mm holes

further parts

Order code

71495126
Zero-point gel COY8

further parts

Order code

COY8-
Zero-point gel COY8

further parts

Order code

COY8-
Zero-point gel COY8

further parts

Order code

COY8-
Zero solution for DO/chlorine sensors

further parts

Order code

50001041
COY 3-SK membrane protective basket

Order code

50081787
Calibration cap, COS31/41/61/51D/61D//71

Order code

51518599
Cleaning head COS61/61D, 6 or 8mm

Order code

71110801
Cleaning head COS61/61D 1/4"

Order code

71110802
Cleaning unit, 230 V

Order code

71072583
115 VAC 2 output compr.air cleaning unit

Order code

71194623
Junction box RM

Order code

51500832

Digital oxygen sensorOxymax COS61D

Memosens optical oxygen sensor for water, wastewater and utilities

Specs at a glance

Measuring range

Process temperature

Process pressure

Field of application

Benefits

Videos

Extended selection

Success stories

Monitoring water quality in fish farms

Toilet flushing with a fresh sea breeze

50% less precipitant - 100% reliability and cooperation

An automated system for pH measurements at AVR

Automated pH measuring point in wastewater

Could also interest you

Liquiline: cutting-edge transmitter platform

Memosens 2.0: Cutting-edge sensor technology reloaded

Measuring principle

Application

Characteristic

Measuring range

Measuring principle

Design

Material

Dimension

Process temperature

Process pressure

Temperature sensor

Connection

Back

COV61 maintenance kits COS61/COS61x

Sensor cap, COS61,COS61D, 1 piece

Sealing set,SensorCOS61,COS61D2pieces

Kit COSxx Protection cage Standard

Protectiv.cage for COS31/41/51D/61/71

Kit COSxx Protection cage Fish farming

Kit COSxx Protection cage 8,5 mm holes

Zero-point gel COY8

Zero-point gel COY8

Zero-point gel COY8

Zero solution for DO/chlorine sensors

COY 3-SK membrane protective basket

Calibration cap, COS31/41/61/51D/61D//71

Cleaning head COS61/61D, 6 or 8mm

Cleaning head COS61/61D 1/4"

Cleaning unit, 230 V

115 VAC 2 output compr.air cleaning unit

Junction box RM

Choose from our suggested options

Individual configuration

Often bought together

Products & Services

Industries

Support

Company

We value your privacy

Digital oxygen sensor
Oxymax COS61D