A MODEL OF THE TRANSIENT-RESPONSE OF MASS-TRANSFER LIMITED GAS SENSORS

A model for the transient response of a mass-transfer limited electroc hemical gas sensor is developed to describe the sensor behavior in the presence of a mixture of oxygen and one oxidizable (and possibly oxyg enated) generic hydrocarbon, ClHmOn (i.e. CO, C3H5OH, H-2, CH4, C3H8, C3H6...) in an inert carrier gas such as N-2. The goal is to predict t he time dependent sensor output resulting from a time dependent gas co mposition. The model is developed for a metal oxide sensor but can eas ily be adapted to other types of material. In principle, the model cou ld also be extended to other gas environments. The model is shown to a gree well with experiment under both steady state and transient condit ions. (C) 1997 Elsevier Science S.A.