Effect of humidity on the sensing property of thermoelectric hydrogen sensor

Gas responses of thermoelectric hydrogen sensors in dry and humid atmospheres were measured to investigate the effect of humidity. The gas responses of the thermoelectric hydrogen sensor were not affected by the humidity in condition of 55 and 75% RH when the devise-operating temperature was 60–100 °C, however, the gas response decreased when the devise-operating temperature was at room temperature. A gas flow chamber and a gas diffusion chamber were used to measure the gas responses and the similar results were obtained from both methods. In situ FT-IR measurements were carried out to examine the state of the hydrogen oxidation on the catalyst surface by the detection of generated water molecules.