Oxygen sensors measure dissolved oxygen concentration in seawater.
The Aanderaa Optode determines the in-situ oxygen concentration based on the ability of the sensing foil (platinum porphyrine) to act as a dynamic fluorescence quencher. Fluorescence is the ability of a molecule to absorb light of certain energy and then emit light with lower energy. The Optode excites its sensing foil by exposing it to a modulated blue-green light source, and due to its fluorescent behaviour, the foil then returns red light (longer wavelength, lower energy). The lower wavelength photon that is emitted is delayed by the presence of oxygen molecules, and the amount of oxygen determines the lag in time (or phase shift) between excitation of the foil and detection of the returned red light. By linearizing and temperature compensating this phase shift, the absolute oxygen concentration can be determined.
The SBE 43 uses a Clark polarographic membrane type (see image). In these sensors, oxygen molecules diffuse through a membrane and are converted at a gold cathode to hydroxyl ions (OH-). The rate of diffusion of oxygen molecules leads to a measurable electrical current that the sensor electronics converts to a voltage. The voltage signal is linear with partial pressure of oxygen. Taking temperature, salinity, and pressure into account, oxygen concentration can be calculated.
Sea-bird SBE63 Oxygen Sensors are designed to be integrated with Sea-bird CTD such as the 16plus V2, 37SIP and 19plus models and utilise the same optical principles of the Aanderaa Optode for measurement. The SBE 63 is designed for use in the pumped flow path of a CTD. Water does not freely flow through the plumbing between samples, allowing anti-foul concentration inside the system to maintain saturation and eliminating exposure of the sensor to light, maximizing bio-fouling protection. The elapsed time between the CTD and associated oxygen measurement is easily quantified, and corrected for in post-processing.
The Alec RINKO is a fast-response, high accuracy and high- resolution oxygen sensor based on an optical (phosphorescence) principle.
Individual instruments of the above category, which are (or have been) connected to our observatories. Click an instrument for detailed information.
|Aanderaa Optode 3830 (S/N 871)||Ocean Networks Canada Offices|
|Aanderaa Optode 3830 (S/N 910)||Marine Technology Centre|
|Aanderaa Optode 3830 (S/N 911)||Marine Technology Centre|
|Aanderaa Optode 3835 (S/N 1415)||Marine Technology Centre|
|Aanderaa Optode 3835 (S/N 1416)||British Columbia Ferries|
|Aanderaa Optode 3835 (S/N 1417)||Marine Technology Centre|
|Aanderaa Optode 3835 (S/N 1797)||British Columbia Ferries|
|Aanderaa Optode 3835 (S/N 224)||Ocean Networks Canada Offices|
|Aanderaa Optode 3835 (S/N 418)||Marine Technology Centre|
|Aanderaa Optode 4175 (S/N 0580)||Marine Technology Centre|
|Aanderaa Optode 4175 (S/N 0581)||Marine Technology Centre|
|Aanderaa Optode 4175 (S/N 1684)||Marine Technology Centre|
|Aanderaa Optode 4175 (S/N 18)||Marine Technology Centre|
|Aanderaa Optode 4175 (S/N 579)||Marine Technology Centre|
|Aanderaa Optode 4175C (S/N 0793)||Marine Technology Centre|
Click the instrument categories below for descriptions and lists of instruments belonging to that category.