Thus, an electromotive force (EMF) proportional to the difference in oxygen concentrations on either side is generated between the two platinum electrodes. The core components of the oxygen sensor—also known as the zirconia concentration cell—are formed by the zirconia electrolyte tube, the porous platinum electrodes on either side, and the gases of different oxygen concentrations on either side. The fundamental driving force for the generation of the EMF in this battery comes from the difference in oxygen chemical potential between the environments of the electrodes on either side. In practical oxygen probe applications, the side with higher oxygen concentration usually has a gas of known oxygen concentration introduced as the reference gas, such as air (where Pref ≈ 20.6%). Through theoretical derivation and combining relevant constant terms, when the reference gas is air,