How Suitable are ‘Low Cost’ Sensor Systems for LAQM monitoring?
There has been a significant growth in the development of low-cost sensor systems capable of measuring air pollutants in recent years, and both the technology and methods of operation continue to evolve rapidly. Typically, these instruments represent a lower capital investment cost when compared to more complex continuous methods of monitoring, and their use can reduce the extent of running costs over a yearly period. As such, they are an attractive option that allows measurements to be undertaken at improved spatial and temporal resolutions. However, this comes with a trade-off on the accuracy and precision of the measurements being made.
Details are given below of the current status of certification schemes for sensor systems. Due consideration will be given with respect to their applicability for use in reporting against the LAQM objectives, identifying ‘hot-spots’, elucidating trends, or identifying pollution causing activities.
For gaseous (NO, NO2, CO, O3 or SO2) sensor systems there is no current certification scheme, and therefore it is not possible to distinguish which the better sensor systems are until this is in place. A European Certification Scheme for gaseous (NO, NO2, CO, O3 or SO2) sensor systems is currently under development.
For particulate sensor systems, a similar European scheme is under development. Additionally for particulates, there exist a number of PM10 and PM2.5 monitors that have been certified as suitable for indicative monitoring within the UK (see Technical Guidance LAQM.TG(22) para 7.175 and/or Technical Guidance LLAQM.TG(16) para 4.53).
For more information on low-cost sensor systems, please refer to the Air Quality Expert Group’s advice.