Resolving fast gas transients with Metal-Oxide sensors

Electronic olfaction can help detect and localise harmful gases and pollutants, but the turbulence of natural environment presents a particular challenge: odor encounters are intermittent, and an effective electronic nose must therefore be able to resolve short odor pulses. The slow responses of the widely-used Metal-Oxide (MOX) gas sensors complicate the task. Here we combine high-resolution data acquisition with a processing method based on Kalman filtering and absolute-deadband sampling to extract fast transients. We find that our system can resolve the precise time of odor onset events, allowing direction estimation with a pair of MOX sensors in stereo-osmic configuration.