The open AirSensEUR monitoring system generates air-pollution data from accessible low-cost sensors, helping citizen scientists contribute better to environmental data.
More and more citizens are monitoring air quality in their local micro-environment. However, the hardware citizens can usually afford generates data that does not meet the quality criteria for official data. More accurate equipment exists but it is expensive, restricted in scope or limited by intellectual property restrictions.
The AirSensEUR project has therefore developed a low-cost battery-operated device that can monitor a wide range of air pollutants at low concentrations. The system, which costs about EUR 1 000 to build, can mount four amperometric low-cost sensors from any of the major international sensor manufacturers to measure individual chemicals. The standard set of pollutants includes O3, NO, NO2 and CO as well as temperature, pressure and relative humidity.
The AirSensEUR system is made up of three parts – sensor shields and a host board within the device, and open-source programs to run the system. Each shield contains a daughter board with built-in temperature, pressure and humidity sensors along with the amperometric sensors. The host board, powered by a LiFePO4 battery, collects the time-stamped measurements from the shields, combines them with geographical coordinates and links to an external database and the user interface, via WiFi, GPS, GSM, USB, DART and a 12C SPI PWN points. Dedicated firmware runs the device, while software for external devices allows users to configure the set-up and download data.
Measurements are stored within the device and are pushed periodically to an external database. Pollution data can also be combined with GPS information to use in maps.
The device uses open software and hardware so that it can be part of a multi-sensor network. Based on the Sensor Observation Service (SOS) interface standard of the Open Geospatial Consortium (OGC), it can ‘plug’ into a spatial data infrastructure that combines data from different sources, so that researchers can find possible impacts of pollution or monitor risks to people. In order to ease integration with public sector information, the AirSensEUR system particularly follows the standards of the Infrastructure for Spatial Information in the European Community (INSPIRE).
Laboratory tests suggest that AirSensEUR is easy to configure and is sensitive enough to measure expected levels of air pollution in background and traffic sites in rural, urban and suburban areas. It can record large amounts of data – one shield took over 4 million observations during the tests.
AirSensEUR provides the tools for citizens to contribute to public information through the growing Internet of Things. All documentation to build the device, including CAD designs for printing the housing, is freely available from the JRC and partners.