Useable anywhere, the WTW Oxi 3205 and Oxi 3210 handheld
dissolved oxygen meters are robust, easy to operate and provide
assured accurate readings. Both handheld dissolved oxygen
meters meet IP66/67 standards – no worrying about using it in
the rain and mud, or accidentally dropping it in the water.
These handheld dissolved oxygen meters have incorporated a
sealed silicone keypad which offers real button response, yet
allows for easy cleaning. In combination with galvanic oxygen
meter probes DurOx® 325
or CellOx® 325 (no
polarization time required) the handheld dissolved oxygen meters
are ready for immediate use anywhere.
Oxi 3205 handheld dissolved oxygen meters
This easy to use handheld dissolved oxygen meter will meet all
your day-to-day demands. This simple, robust dissolved oxygen
handheld meter has a simplified keypad, with no memory function
and no manual input facilities. When used in combination with
the DurOx® 325 dissolved
oxygen meter probe and its protective hood the handheld DO
meter is particularly suitable for measurements in fish-farming
Oxi 3210 handheld dissolved oxygen meters
The compact precision handheld dissolved oxygen meter Oxi 3210
enables you to carry out oxygen (DO) measurements rapidly and
reliably. The Oxi3210 handheld dissolved oxygen meters provide
the maximum degree of operating comfort, reliability, and
measuring certainty for all applications. Loaded with
additional features, the Oxi 3210 handheld DO meters include
automatic temperature and air pressure compensation, salinity
correction, GLP-supporting functions and built in datalogger.
The handheld dissolved oxygen meters also have auto ranging and
auto read function, which checks the stability of the input
signal, for ease of use and data reproducibility. The handheld
dissolved oxygen meters have a continuous measurement control
(CMC) function that alerts you when your meter is reading
outside of the calibrated range. The handheld dissolved oxygen
meter's large memory allows you to manually store 200 datasets.
What is Dissolved Oxygen?
Some oxygen is dissolved in practically every liquid. For
example, at a temperature of 68 °F (20 °C) and an atmospheric
pressure of 1013 mbar saturated water contains about 9 mg/l
oxygen. Ethanol can contain up to 40 mg/l whereas glycerol only
has about 2 mg/l.
Each liquid takes up oxygen until the partial pressure of
oxygen in the liquid is in equilibrium with the air or gas phase
in contact with it. The actual oxygen concentration depends on
a number of factors, such as temperature, air pressure, oxygen
consumption by microorganisms in a biodegradation process or
oxygen production by algae, etc.
The oxygen concentration is important for the:
- Living conditions for fish and microorganisms in waters
- Degradation processes in wastewater treatment
- Corrosion processes in pipelines
- Shelf life of beverages, etc.
The determination of the dissolved oxygen concentration was
formerly carried out by the WINKLER titration method. Today
electrochemical measurement is a recognized method in numerous
In its simplest form a dissolved oxygen sensor contains a
working electrode and a counterelectrode. Both electrodes are
located in an electrolyte system which is separated from the
sample by a gas-permeable membrane. The working electrode
reduces the oxygen molecules to hydroxide ions. In this
electrochemical reaction a current flows from the
counterelectrode to the working electrode. The more dissolved
oxygen present in the sample, the larger the current signal.
The handheld dissolved oxygen meter calculates the oxygen
concentration in the sample from this signal.