Handheld DO meter for field measurements.
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 applications.
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:
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 standard procedures.
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.