The Study Of Bell Socket And Electrode Of Solid Electrolyte Hydrogen Sensor

Based on the mechanism of Proton Solid Electrolyte Fuel Cell, a solid electrolytic type of hydrogen concentration sensor working in the temperature range of 300⁸50℃is developed, which could be used for the instant measurement and control of hydrogen concentration with precision.Various types of solid electrolytes were examined for their feasibilities of producing transducers and the material of BaCeO₃ with Yb dopant was chosen to make the hydrogen concentration sensor. Thermo expansion rate was first measured by a trial production and aΦ10.1mm×9.9mm cylinder of solid electrolyte was then sintered using a mould adjusted accordingly.The seal connection between solid electrolyte and casing pipe was examined in terms of various sealing materials and their effects on sealing level, insulation, and compressive shear strength. Tests show that the process of inorganic phosphate and copper oxide adhesive plus end glazing has the best result meeting the demands of transducer manufacturing in terms of gas tightness, insulation, and compressive shear strength.Various hydrogen sensor types of different internal/external electrode structures, materials, manufacturing processes were examined and a conclusion was drawn on each different electrode structure and its suitable applications.In conclusion, a hydrogen concentration sensor was manufactured by adhering solid electrolyte cylinder to high alumina ceramic tube with inorganic phosphate and copper oxide adhesive plus end glazing with assembling internal electrode and external electrode by conductive film sintered with palladium-silver conductive slurry. At the temperature of 560℃, with internal atmosphere as the reference, the concentration of hydrogen and the output voltage of the hydrogen concentration sensor is well related, at the same time, sensor output voltage is very sensitive to hydrogen concentration. Tests show that the developed sensor has a high repeatability and could be used for hydrogen measurements and control in specific environment.