A new type of oxygen sensor using the electrochemical oxygen pump of a zirconia electrolyte and the artificial oxygen diffusion overpotential behavior has been investigated from the theoretical and practical viewpoints of the "gas polarography," the concept of which is proposed in this paper. This new oxygen sensor has excellent oxygen sensing characteristics analogous to polarography. As a result of the artificial oxygen diffusion overpotential at the cathode, the reproducible limiting current relating to the oxygen concentration was observed over a wide oxygen concentration range up to 95% and a temperature range of 400~176 in O2-inert gas mixtures. In this paper, the factors influencing the limiting current in the normal diffusion region, that is, the oxygen molar fraction, gaseous diffusion coefficients, the temperature, the pressure, and the two geometric quantities (area and length) of the gas diffusion hole are theoretically considered.
N2O-gas sensing in N2O-O2 and N2O-N2 gas mixtures was investigated using a gas polarographic oxygen sensor which was operated at 500°C. The sensor detected the gaseous oxygen formed by the thermal decomposition of N2O; consequently, the output of the sensor agreed well with that calculated on the basis of the assumption that N2O was fully decomposed into O2 and N2 gases.
A gas polarographic oxygen sensor using a yttria‐stabilized ZrO2 electrolyte is investigated theoretically and experimentally with special emphasis on the factors influencing the limiting current in the normal diffusion region (temp., pressure, molar oxygen fraction, diffusion coefficients, area and length of the gas diffusion hole).
The hydrogen-sensing capability of a gas polarographic oxygen sensor using a zirconia electrolyte has been investigated at 450°C and 1 atm in H2-N2 gas mixtures. The limiting current was realized in H2-N2 gas mixtures due to the artificial hydrogen diffusion overpotential behavior at the anode, and is proportional to the hydrogen concentration up to 5% in H2-N2 gas mixtures. This result proved that this oxygen sensor can also detect the hydrogen in H2-inert-gas mixtures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.