Sensors and Sensor Networks for Air Quality Monitoring

CNR-IMM Bologna, Via P. Gobetti 101, 41029 Bologna, Italy


While several low-cost gas sensing technologies exist and are commercially available, the sample matrix to be analyzed in air quality monitoring applications is complex, resulting in very challenging sensing requirements. Certified instrumentation used by public authorities to monitor air pollution is bulky, expensive and sometimes complex to operate, and the development of new devices based on low-cost autonomous sensors is attracting the attention of numerous research groups and companies.

After a review of sensor requirements for outdoor and indoor air quality monitoring applications, several gas sensing technologies will be introduced (including metal-oxide, photoionization, electrochemical, spectrophotometry, gas-chromatography, optical particle counters), together with some commercial low-cost devices, describing their main features and discussing their limitations.

After a brief description of sensor networks, their specific requirements in the field of air quality monitoring will be discussed, together with some embedded hardware and open-source software suitable to take the sensors into the field. We will briefly review an example of a network communication protocol specifically developed for the transport of sensor data.

Finally, some of the best available technologies for the implementation of distributed low-cost sensor networks in the framework of “citizen science” and “smart cities” applications will be reviewed, with particular attention in evaluating the feasibility of acquiring reliable air quality data.


Stefano Zampolli graduated in physics at the University of Bologna in 2000, discussing a thesis on the application of Fuzzy Logic for detection of buried landmines. He is a grant student at CNR-IMM Bologna since April 2000, working primarily on gas sensor characterization and data processing within the sensor and microsystem R&D program. Since 2005 he is researcher in the sensors and microsystem group at CNR-IMM, designing and developing gas sensors and gas sensing Microsystems for environmental monitoring, agro-food and security applications. Starting in FP5, he has participated to 7 European Projects, has active collaborations with several SMEs, has relevant expertise in technology transfer and is currently leading the CNR IMM Bologna MEMS gas sensors group.