Analyses of the ammonia response of integrated gas sensors working in pulsed mode

WO3–Cr, SnO2–Pd and TiO2–Cr nanoparticles have been prepared following a sol–gel route. The additive-modified nanostructured metal oxides have been deposited on hotplate platforms by microdropping. Functional gas test of the sensitive layers to ammonia has been performed in stationary and pulsed mode of operation. The pulsed mode fastened the regeneration of the surface yielding an enlargement of the sensor response and a decrease of the transient time. The improved sensing response to ammonia was particularly marked for the WO3–Cr based gas sensor.