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Subsea oxygen sensor

CONTROS HydroFlash O2

HydroFlash O2 subsea, shallow / deep water oxygen sensor

The CONTROS HydroFlash® O2 optode is a versatile subsea, shallow and deep-water oxygen sensor which can be used for autonomous deployments as well as integrated into sensor systems. The CONTROS HydroFlash® O2 is designed for a wide variety of deployment schemes and platforms including but not limited to AUVs, gliders, floats, water sampling rosettes, buoys, and moorings.

Individual 'in-situ' calibration

The optode head has a unique design featuring an anti-fouling head, a fast response temperature probe and a curved glass substrate coated with the sensing membrane. All sensors are individually calibrated in a water tank over a wide range of temperatures and oxygen concentrations. An established laboratory method ('Winkler test') is used to ensure the quality of the calibration.

Operating principle

The advanced, optical sensor is based on the principle of fluorescence quenching. Dissolved oxygen (O2) molecules diffuse into a membrane in which a fluorescent dye is embedded. Oxygen is capable of quenching this fluorescence by transferring the excitation energy from the dye to the O2 molecule. The sensor repeatedly excites the dye in the membrane and measures the intensity and phase shift of the fluorescence light. The more O2 is present in the water, the smaller is the measured fluorescence signal and the higher is the phase shift.


  • Highly efficient fluorescent dye embedded on a curved, solid substrate to enhance light yield
  • Very fast response time (t63 < 3 s) combined with high stability and accuracy
  • Versatile - easy integration into almost every oceanographic measurement system and platform
  • Robust - can be used in water depths up to 6000 meters
  • Titanium housing with small dimensions
  • Very low power consumption
  • Programmable sleep mode extends battery lifetime during autonomous deployment
  • Comprehensive software for programming, data download and visualization included
  • Non-consumptive O2 measurement


  • Flow head
  • Autonomous deployment with CONTROS HydroB® Flash (attachable battery) possible
  • Easy deployments together with CO2 and CH4 sensors
  • ROV and AUV installation packages
  • Profiling and mooring frames


KONGSBERG provides a dedicated power solution for the CONTROS HydroFlash® O2 optode, the CONTROS HydroB® Flash. Its simple yet efficient "plug-and-play" design allows for autonomous deployments of up to three months.

Services & Aftermarket Support

24/7 Technical Support

Our 24/7 technical support team is there to help at any time, day or night, wherever your vessel is. We will manage your call from the time it is received to the time the issue is resolved.

The team has direct access to the experts in our product centres, should additional support be required, and for the more complex issues a product specialist will be assigned to you. Our priority is to get the right expertise quickly matched with the issue to provide the answers you need.

Contact us

The following contact information will put you through to our global support team:


We understand the importance of having the right parts, available in the right place, at the right time.

We have streamlined our operations to reduce lead-times and increase spares availability.

Contact us

Our 24/7 technical support team is there to help at any time of day or night wherever your vessel is located. They manage your call from the time it is received to the time the issue is resolved.

Contacting any of these numbers will put you through to our global support team:

Our local representatives will respond to your support requirements 24/7. If you want to know more about how our enhanced service delivery will benefit you, please contact our nearest Office.

Product Training

Ensure that your crew is properly and thoroughly trained. This will reduce operational risk, downtime and maximise return on asset investment.

It also enables you to meet regulatory standards, improve crew safety and retain key personnel. In our state of the art training centres qualified and experienced trainers are able to provide your crew with practical training tailored to suit your products, systems and operational requirements. Our instructors can also train your crew on-board your vessel.

From hands on experience on live products in our training centres, to experiencing real life scenarios in our world class simulators all our courses are designed to focus on efficient and safe operation and maintenance of your Kongsberg Maritime equipment.


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This type of solution is ideal for theoretical training, especially for larger groups. It goes through detailed systems overview including drawings and functionality.

This type of solution is ideal for practical training with focus on maintenance and troubleshooting on actual products. This type of training used together with classroom training can provide a holistic view of complete systems.