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.
Several gas sensing technologies will be introduced (including advances in metal-oxide, photoionization, infrared absorption, electrochemical, optical particle counters) starting from 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 a examples of a network communication protocol (MQTT) specifically developed for the transport of sensor data.
This talk will give an overview of 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, with particular attention in evaluating the feasibility of acquiring reliable air quality data.