Oxygen dependency of the hydrogen sensor based on high-temperature proton conductors

Oxygen dependency of the hydrogen sensor using high-temperature proton conductors with titanium/titanium hydride solid reference material was studied. It was found that the oxygen in a measuring atmosphere led to a considerable p-type conduction which was responsible for the instability of the sensor electromagnetic field (EMF). The sensor EMF increased continuously due to the insertion of protons and decreased due to the depletion of protons upon exposure to an oxidizing atmosphere. It is revealed that the EMF behavior of the sensor is decided by the electronic conduction that relatively changed with hydrogen concentration in a highly oxidizing atmosphere. The transient behavior of the hydrogen sensor under various atmospheres containing oxygen was discussed in this work.