Development of a reliable methane detector

Present commercial combustible detectors (semiconductors or pellistors) are basically non-selective and they could lead to a non-neglectable rate of false alarms. In order to solve the selectivity problem, we have designed a detection system based on the differential catalytic activity uf platinum and palladium, versus the oxidation of methane. Two detesters based on semiconductor oxides and/or pellistors and their electronic control circuits are presented. The results of the whole system and long term stability are finally given and discussed. (C) 1997 Published by Elsevier Science S.A.