Behaviour of a catalytic combustion methane gas sensor working on pulse mode

A catalytic combustion type methane gas sensor with Pd-Pt/ γ-Al₂O₃ catalyst working on pulse voltage mode is investigated in this paper, after fabricated by micromachining and sol-gel process on a silicon substrate. In order to achieve low power consumption as well as high sensitivity, pulse voltage was applied to a bridge circuit consisted of the sensor, and the ratio of the gas sensitivity to power consumption was considered as an optimizing factor when selecting high level voltage. Outputs from four low level voltages indicate that the response time of the sensor decreases with the increasing low level voltage, while the sensitivity is almost 1.8 times of the value working on constant voltage in some cases, which path a way to improve the performance of the sensor.