The O₂.sens from Wi.Tec is based on an electrochemical process. In this process, a chemical reaction takes place with the oxygen to be measured and a liquid electrolyte. During this reaction, 4 electrons are released per oxygen molecule. The resulting sensor current IM or the measuring voltage UM increases proportionally with the number of reacting O₂ molecules. This results in a sensor characteristic curve that increases linearly with increasing O₂ concentration.

Principle structure

The liquid electrolyte is located in a sealed chamber, which is sealed on the gas side with a permeable membrane. The oxygen passes through this membrane to the electrolyte and then leads to the described measuring effect. This reaction consumes the anode material, which limits the service life of this sensor. A membrane with a high permeability leads to a high and fast signal change (=short response time), but also to a shorter service life, as more chemical reactions take place per time. Membranes with a low permeability therefore exhibit the opposite behaviour.