Burning type catalyzing gas sensors are the devices of the gas monitoring system in coal mines

which realizes the auto on-off of the ventilation system based on detecting the gas volume fraction.Due to the bad environmental conditions in the mines

gas sensors are limited by the shortcomings of low stability and short calibration periods

which has been a problem to limit the sensors’application.By studying the thermal firing type gas sensors’activation vanishing modes and analyzing the responses

three activation vanishing mechanisms of the Pt catalyst are major discussed

including the firing

coking and toxicosix mechanism.The catalyst’s activation vanishing velocity function is built up.The activation vanishing situation is improved by adding the Pt-Pd complex catalyst.Experimental results demonstrate that the sensor’s stability is apparently improved.