Small sensors are increasingly being used to measure gases and particles in the atmosphere, as part of academic research and in citizen science projects. Their low cost, portability and low power requirements bring new measurement possibilities, for example to improve the spatial representation in air quality monitoring networks. However, to deliver quantitative observations requires that sensor performances should be well-understood and characterised.
Furthermore, sensor behaviour depends on the environment of application. Tjarda Roberts, through research, has deployed small sensors at volcanoes where monitoring of gas emissions informs observatories about volcanic activity and eruption hazards. Alongside this she has deployed small gas and particle sensors to measure the high levels of urban pollution experienced in Fairbanks, Alaska, during the cold Arctic winter. These applications enable (and require) the characterisation of small sensor performances in “extreme environments” and can provide valuable insights to the processes underlying the pollution events.