Technical Details

OdoWatch® : Real-time Odour Monitoring

OdoWatch® merges continuously the odour data with the incoming weather data to display on the screen the odour plume superimposed on a map of the site and its surroundings.

The operator therefore sees the effect of site odours on the neighborhood, at-a-glance. When using meteorological forecast data, OdoWatch® can also predict the odour impact up to 24 hours ahead. This enables the operator to take steps to reduce the odour and prevent the nuisance from occurring.


The OdoWatch® is comprised of three main systems:

  • The Electronic Noses, or "e-noses, " which measure the odours
  • The Central Control Unit, comprised of the OdoWatch® software for atmospheric dispersion modelling
  • Weather tower on-site

Electronic Noses

An Electronic Nose is comprised of the aspirator for sampling, the measurement chamber and the communication system, all contained within a single enclosure.

In each Electronic Nose, a micropump aspirates an air sample once per minute and forwards this to the internal measurement chamber. The optimised sensors in the measurement chamber react differently to odours. (These sensors are not specific to a particular chemical, like other technologies who develop and use H2S sensors, but instead are specific to the odours and processes on your site.) The presence of odourous molecules absorbed by the metal oxide sensor surface modifies the sensor conductance, which alters the output voltage. The sensor signals are treated by the signal processing cards of each Electronic Nose, then sent to the internal communication system.

The Electronic Noses measure odour concentration in odour units at or near the source. The accuracy of the measurement can be verified by comparing the olfactometric result and the EN reading.

Central Control Unit

Each Electronic Nose unit contains a signal transmission system, used to forward the odour readings to the Central Control Unit, a PC equipped with the OdoWatch® software that merges the odour data with the meteorological data from the site weather tower as well as with other parameters in order to determine the odour plume.