A model of the transient response of mass-transfer limited gas sensors

Abstract A model for the transient response of a mass-transfer limited electrochemical gas sensor is developed to describe the sensor behavior in the presence of a mixture of oxygen and one oxidizable (and possibly oxygenated) generic hydrocarbon, C l H m O n (i.e. CO, C 3 H 5 OH, H 2 , CH 4 , C 3 H 8 , C 3 H 6 …) in an inert carrier gas such as N 2 . The goal is to predict the time dependent sensor output resulting from a time dependent gas composition. The model is developed for a metal oxide sensor but can easily be adapted to other types of material. In principle, the model could also be extended to other gas environments. The model is shown to agree well with experiment under both steady state and transient conditions.