Handheld DO meter for field measurements.



  • Robust shock and waterproof design
  • Easy to use interface
  • Wide range of applications
  • Extremely long battery life

Handheld Dissolved Oxygen Meters Product Description

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:

  • 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 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.

Handheld Dissolved Oxygen Meters Specifications

Handheld Dissolved Oxygen Meter Range (both meters):
O2 Concentration*: 0.00 to 19.99 mg/l, 0 to 90 mg/l
O2 Saturation*: 0.0 to 199.9% or 0 to 600%
Partial Pressure*: 0 to 199.9 hPa or 0 to 1250 hPa
Temp: 32 to 221 °F (0 to +105.0 °C)
Handheld Dissolved Oxygen Meter Accuracy (both meters):
O2 Concentration*: ± 0.5 % of measured value at ambient temperature of 41 to 86 °F (5 to 30 °C)
O2 Saturation*: ± 0.5 % of measured value when measuring in the range of ± 10 K around the calibration temperature
Partial Pressure*: ± 0.5 % of of measured value at ambient temperature of 41 to 86 °F (5 to 30 °C)
Temperature: +0.2 °F (+0.1 °C)
Handheld Dissolved Oxygen Meter Resolution (both meters): All values +1 digit
Salinity Correction: 0 to 70 SAL
Air Pressure Correction: Automatic through installation of pressure sensor in the range 500 to 1100 mbar
Operational Temperature: 14 to 131 °F (-10 to 55 °C)
Storage Temperature: -13 to 149 °F (-25 to 65 °C)
Power: Four 1.5 V AA batteries or four 1.2 V NiMH
Battery life: Up to 1000 hours w/o backlight, 150 hours w/ backlight
Dimensions (LxWxH): 6.78×3.15×1.46in (172x80x37mm)
Weight: 0.66lb (0.3kg)
IP Rating: IP 66/67
Certifications: CE
* Depending on sensor

CellOx® 325-3 Probe
Electrode material: Gold (Working), Lead (Counter)
Shaft material: POM
Cable length: 9.8 ft (3 m)
Measuring range: 0 to 50 mg/l O2, 0 to 600% O2
Temperature range: 32 to 122 °F (0 to 50 °C)
Min/max immersion depth: 2.4in to 65ft (6cm to 20m) depending on cable length
Shaft length: 7.38 in (187.5 mm)
Diameter: 0.70 in (17.5 mm)
Weight: 6 oz (170 g)

DurOx® 325-3 Probe
Membrane Head material: POM
Shaft material: POM
Cable length: 9.8 ft (3 m)
Measuring range: 0 to 50 mg/l O2
Temperature range: 32 to 104 °F (0 to 40 °C)
Min/max immersion depth: 1.6in to 9.8ft (4cm to 3m)
Shaft length: 4.33 in (110 mm) with protective hood
Diameter: 0.70 in (17.5 mm)
Weight: 7.8 oz (220 g) with cable

Handheld Dissolved Oxygen Meters Options

Oxi 3205 Set Handheld Dissolved Oxygen Meter Set (PN# 2BA103)
Includes dissolved oxygen meter, DurOx® 325-3 dissolved oxygen probe (9.8ft cable), case & accessories.

Oxi 3210 Set Handheld Dissolved Oxygen Meter Set (PN# 2BA202)
Includes dissolved oxygen meter, CellOx® 325-3 dissolved oxygen probe (9.8ft cable), case & accessories.


CellOx® 325-3 Handheld Dissolved Oxygen Meter Probe (PN# 201545)
Includes 9.8 ft (3m) cable.  Other cable lengths available, Contact Us.

DurOx® 325-3 Handheld Dissolved Oxygen Meter Probe (PN# 201570)
Includes 9.8 ft (3m) cable.


DO600 Dissolved Oxygen Meter
Includes DO electrode, protective sensor cap, spare membrane cap, electrolyte, four 1.5V SR44W batteries, and a 48 inch (1.2m) neckstrap.

DO610 Dissolved Oxygen Probe Kit
Includes EC500 Conductivity/TDS/Salinity/pH/Temperature meter, DO600 Dissolved Oxygen probe, and accessories.

DO200ACC Field Dissolved Oxygen Meter Kit
Includes field DO meter, cable with attached DO/temperature probe, and hard sided case.

3B30-010 Oxi 1970i Portable Dissolved Oxygen Meter w/universal power supply

WQ401 Dissolved Oxygen Sensor