Oxygen Optode 4831/4831F0 pages

Oxygen Optode 4831/4831F
is a compact fully integrated sensor for
measuring the O2 concentration.
Fast Response Foil (4831F, refer overleaf)
Advantages:
• Optical measurement principle
• Lifetime-based luminescence quenching
principle
• Long time stability
• More than one year without recalibration
• Low maintenance needs
• Small size and weight
• Stand-alone sensor
• Output format: RS232, 0-5V
• Three depth ranges maximum 6000 meter

Since oxygen is involved in most of the biological and chemical processes in aquatic
environments, it is one of the most important
parameters to be measured. Oxygen can also
be used as a tracer in oceanographic studies.
For environmental reasons it is critical to
monitor oxygen in areas where the supply of
oxygen is limited compared to demand e.g.
•tIn shallow coastal areas with significant
algae blooms
•tIn fjords or other areas with limited exchange
of water
•tAround fish farms
•tAreas of interest for dumping of mine or
dredging waste
The Aanderaa oxygen optodes are based on
the ability of selected substances to act as
dynamic fluorescence quenchers.
The fluorescent indicator is a special platinum
porphyrin complex embedded in a gas
permeable foil that is exposed to the
surrounding water. For the standard version

4831 a black optical isolation coating protects
the complex from sunlight and fluorescent
particles in the water. This sensing foil is
mounted on a sapphire window providing
optical sampling from inside a watertight
housing.
The lifetime-based luminescence quenching
principle offers the following advantages
over electro-chemical sensors:
•tNot stirring sensitive (it consumes no oxygen)
•tLess affected by fouling
•tMeasures absolute oxygen concentration
without repeated calibrations
•tBetter long-term stability
•tLess affected by pressure
•tPressure behaviour is predictable
•tFaster response time
The oxygen optode outputs data in RS-232
and analog 0-5V. The sensor can present the
O2 concentration in µM, Air Saturation in %
and Temperature in °C.

D403 - Nov 2012