Zirconium Oxide Oxygen Sensors

Zirconium oxide (ZrO₂) sensors, otherwise known as high temperature electrochemical sensors (or hot probes), consist of a cell made of yttria stabilized zirconia ceramic forming a crystal lattice structure which acts as a solid electrolyte.

Typically, the cell is shaped like a test tube where the inner and outer surfaces are each coated with an ultra-thin layer of porous platinum to act as cathode and anode electrodes. At high temperatures (above 650ºC), openings in the crystal lattice permit the movement of oxygen ions. As long as the oxygen partial pressures are equal on both sides, the movement of ions within the lattice is random, and there is no net flow within the lattice.

When a sample gas containing oxygen is introduced on one side, oxygen ions migrate through the crystal lattice to form a concentration gradient from the higher O₂ partial pressure side to the lower pressure side. The gradient, which determines the amount of oxygen in the sample gas, is measured by the ratio of the O₂ partial pressures between a sample gas on one side of the lattice and a reference gas, (typically ambient air) on the other side of the lattice.

At Versaperm we are not tied to any specific sensor types or manufacturer and so we can always select exactly the right sensor for an application. Versaperm is a world technology leader in the measurement of gas permeability. We offer not only instruments but also comprehensive testing and consultancy services.