Dissolved oxygen sensors and dissolved oxygen recorder.


  • Fully encapsulated electronics
  • 4-20 mA output
  • Marine grade cable with strain relief
  • Stainless steel housing
  • Replaceable DO element

Dissolved Oxygen Sensors Product Description

Global Water’s dissolved oxygen sensor is a rugged reliable water oxygen level measuring device. The dissolved oxygen sensors are attached to 25′ of marine grade cable, with lengths up to 500 ft available upon request. The dissolved oxygen sensor output is 4-20 mA with a three wire configuration. The dissolved oxygen sensor’s electronics are completely encapsulated in marine grade epoxy within a stainless steel housing (online version has 1×8 inch PVC pipe nipple, threaded both ends with cap). The dissolved oxygen sensor uses a removable shield and dissolved oxygen element for easy maintenance.

Global Water’s PC320 Dissolved Oxygen Controller to use the dissolved oxygen sensor’s output to control pumps or alarms.  In addition Global Water offers GL500 dissolved oxygen recorder adds recording capabilities to the dissolved oxygen sensor.  The GL500 dissolved oxygen recorder connects to the dissolved oxygen sensor’s 4-20mA output to record data.

Why Measure DO?
Dissolved oxygen (DO) is the amount of oxygen (O2) dissolved in water.  Dissolved oxygen measurements provide one of the best indicators of the health of a water ecosystem, as oxygen is a necessary element for all forms of life, including aquatic life.  Oxygen enters water at the water surface through direct exchanges with the atmosphere.  It is also produced as a byproduct of plant and phytoplankton photosynthesis.  A decrease in dissolved oxygen levels is typically associated with an organic pollutant.  Dissolved oxygen is used by plants and animals for respiration, and by aerobic bacteria in the process of decomposition.  When organic matter (such as animal waste or improperly treated wastewater) enters a body of water, algae growth increases.  As the plant material dies off and decomposes, dissolved oxygen levels decrease.  If the water at the surface is not mixed with deeper water layers, the water’s dissolved oxygen levels can become stratified.  Dissolved oxygen levels can also vary according to the time of day, weather, and temperature.  Dissolved oxygen in water can range from 0-18 parts per million (ppm), but most natural water systems require 5-6 ppm to support a diverse population.  As dissolved oxygen levels drop below 5.0 mg/L, aquatic life is put under stress.  As dissolved oxygen levels decrease, pollution-intolerant organisms are replaced by pollution-tolerant worms and fly larvae.  If dissolved oxygen levels fall below 1-2 mg/L for a few hours, large fish kills can result.

Dissolved Oxygen Sensors Specifications

Output: 4-20 mA
Range: 0-100% Saturation, 0-8 ppm, temperature compensated to 77°F (25°C)
Accuracy: ±0.5% of full scale
Maximum Pressure: 40 psi
Operating Voltage: 10-36 VDC
Current Draw: 15.5 mA plus sensor output
Warm Up Time: 10 seconds minimum
Operating Temperature: -40 to +131°F (-40 to +55°C)
Membrane: 0.001 FEP Teflon (standard)
Combined Error: 2% FS
Size of Probe:
Standard: 11″ L x 1-1/4″ Diameter (27.9 cm L x 3.2 cm Dia.)
Online: 12″ L x 2″ Diameter (30.5 cm L x 5 cm Dia.) (end cap)
Weight: Standard and Online 1 lb. (454 kg)

Dissolved Oxygen Sensor Options

WQ401 Dissolved Oxygen Sensor (PN# DD0000)
Includes 25 ft of cable.

WQ401-O Online Dissolved Oxygen Sensor (PN# DDA000)
Comes with 1 inch NPT PVC housing. Includes 25 ft of cable.

WQEXC Extra Cable (PN# DH0000)
Standard dissolved oxygen sensors include 25 ft of cable, but can be purchased with up to 500 ft of cable.

Dissolved Oxygen Sensor Electrode (PN# 00-740)
Dissolved Oxygen electrodes should be replaced every six months and calibration should be done after every replacement.


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
Measure 6 water quality parameters.

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

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

Oxi 1970i Portable Dissolved Oxygen Meter w/universal power supply

WQMS Water Quality Monitoring System
The standard unit includes a datalogger, temperature sensor, pH sensor, conductivity sensor (with a 0-5000µS range unless otherwise specified), and DO sensor.

GL500 Dissolved Oxygen Recorder
Dissolved oxygen recorder for sensor datalogging. Includes Global Logger Software. With weather proof enclosure and 12V battery.

PC320 Dissolved Oxygen Controller

EZ100 Dissolved Oxygen Transmitter Display
LCD readout display for both portable use and permanent installations.