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O2 Microsensor

High performance microsensor

The Unisense oxygen microsensor is an excellent research tool for high quality oxygen measurements. The microsensor can be made with tip sizes of only 2-3 µm allowing for non-destructive measurements of oxygen at high spatial resolution in numerous applications. The response time can be less than 0,3 sec and the oxygen microsensor has an insignificant oxygen consumption giving you fast and accurate oxygen measurements.

The oxygen microsensor is designed for research applications within:

  • Environmental sciences
  • Biomedical sciences
  • Biotechnology
  • Microbiology

Oxygen microsensor principle:

The oxygen micro- and minisensors are all Clark-type sensors measuring oxygen partial pressure. The working principle of the oxygen microsensor is based on diffusion of oxygen through a silicone membrane to an oxygen reducing cathode. The reducing cathode is polarized against an internal Ag/AgCl anode.

The oxygen microsensor has a guard cathode that removes oxygen in the electrolyte, thus minimizing zero-current and pre-polarization time. The resulting sensor signal is in the pA range and is measured by a high quality picoammeter e.g. the Unisense Microsensor Multimeter.

 Ordering information 

Standard glass sensor Outside tip diameter
OX-10 8-12 µm
OX-25 20-30 µm
OX-50 40-60 µm
OX-100 90-110 µm
OX-200 175-225 µm
OX-500 400-600 µm
OX-MR 400-600 µm
OX-N 1,1 x 40 mm - needle sensor
OX-NP 1,6 x 40 mm - needle sensor for piercing
OX-Eddy 150-200 µm - Fast responding and low stirring sensitive sensor

Find complete oxygen microsensor specifications, including warranty and expected life time, below and possible microsensor customizations and adaptations under Related Products found to the right.

View Oxygen Sensor Specifications

Technical information

View sensor specifications

Measuring Oxygen

Measuring Oxygen

Measuring oxygen - Optode or amperometric microsensor?

Watch Video Guide
O<sub>2</sub> Calibration Kit Video

O2 Calibration Kit Video

Watch our complete guide to calibrating a Unisense Oxygen sensor using our O2 Calibration Kit

Watch Video Guide

Related products

Sensor Customization
Profiles in salty crusts

Profiles in salty crusts

Unisense microsensors were succesfully applied to measure salty crusts in the Red Sea in Israel. 

Read more

R (1989), An oxygen microsensor with a guard cathode, Limnology and Oceanography, 474 - 478, vol. 34 Read abstract

Lackner, Susanne et al (2010), Nitritation performance in membrane-aerated biofilm reactors differs from conventional biofilm systems, Water Research, 6073 - 6084, vol. 44 Read abstract

Lecoq, Je et al (2009), Odor-Evoked Oxygen Consumption by Action Potential and Synaptic Transmission in the Olfactory Bulb, Journal of Neuroscience, 1424 - 1433, vol. 29 Read abstract

Evron, Yoav et al (2018), Long-term viability and function of transplanted islets macroencapsulated at high density are achieved by enhanced oxygen supply, Scientific Reports, 6508 - , vol. 8 Read abstract

Choquel, Constance et al (2020), Total nitrate uptake by an invasive benthic foraminifer in marine sediments, Biogeosciences Discussions, 1 - 33, vol.

See all publications