OxyGuard Standard Probe

The OxyGuard probe is a membrane covered galvanic cell that generates an electrical signal proportional to the oxygen pressure it senses, no matter whether it is in water, air or another medium. The OxyGuard probe is very robust and easy to use. It does not need an external supply - it makes its own electricity. The OxyGuard probe is connected using ordinary cable, and can be placed as required - there is no restriction on cable length. It can measure at a depth of 100 meters or more. The membrane can be wiped with a cloth, a tissue or even with your thumb!.

Cleaning the membrane is, apart from an occasional calibration, the only routine maintenance necessary. Probes for use at lower oxygen concentrations (e.g. in waste water treatment) never need service unless the membrane is damaged - and the membrane is very tough. Probes for use at higher oxygen concentrations can, after some 5 years' use, need renovation - which takes just two minutes to perform!

Technical Advantages

  • Extremely high stability - zero adjustment is never needed, calibration seldom.
  • No regular maintenance needs. The robust membrane, 50 µ thick, is easily cleaned, but if damaged can be replaced by anyone - at negligible cost.
  • Correct measurements with flow as low as 1 cm/s.
  • Based on a chemical principle superior to that of traditional DO probes.
  • Galvanic type - True zero.
  • Built-in temperature compensation.
  • No practical limit to cable length - extension can be made with any type of cable.
  • Wide range of armatures and fixtures - e.g. the Air Alarm for worker safety in areas where fluctuating oxygen levels could occur in the air, a Flow Cell for measuring gases etc. Ask for details.
  • Wide range of accessories - e.g. the Easy Cal calibrator, OxyClean compressed air cleaner etc


Standard Probe

Dimensions: Diameter = 58 mm, length = 59 mm. Standard cable length = 5 m.

Weight: Approx. 450 g incl. cable.

Measurement Principle: Galvanic cell, self polarizing, self temperature compensating.

Range and Output: 2.5 to 5 millivolts per ppm(mg/l). Output impedance approx. 1 kiloohm.

Flow Requirements, water: Minimum flow dependent on DO and temperature, typically 1 cm/sec.

Supplied With: Junction box with cable glands etc., spare cap fitted with membrane, 50 ml electrolyte, spare anode.

Ordering Information

Choose the probe that suits your use from the following, which shows the oxygen levels that the particular model is best suited to measure. If you cannot find the one you need please consult OxyGuard - we have a wide variety of special versions. Please state the desired range when ordering.

OxyGuard Standard 2-wire oxygen probes:

You can also obtain probes that incorporate temperature sensors - these have the same ranges as above, just replace D022 with D024 for a probe with a precision NTC sensor or with D025 for a probe with a PT100 sensor. These have 4 and 5 core cables respectively.

All of these can be ordered with an M18 threaded part at the top for screwing into a flange: add the suffix M18 for this option.