The team at AQMesh continue to receive many enquiries from smart city initiatives and are concerned that integrators risk undermining entire projects by distributing meaningless or misleading air quality information.
“Many of the people I speak to are used to dealing with sensors that are easy to ‘plug and play’ and expect to be able to do the same with air quality sensors. This is not helped by the fact that most air quality sensors, sensor systems or ‘nodes’, on the face of it, offer very similar specifications”, comments Amanda Billingsley, AQMesh Director. “Quite understandably, IoT professionals do not generally have a background in air quality measurement and are not aware how notoriously difficult it is to get good air quality readings from small sensors, particularly nitrogen dioxide which is known to be so harmful and a key component of diesel fumes – now classified by WHO as a carcinogen.”
Most of the air quality sensors that are small, cheap and low enough energy for IoT applications also have limitations, such as the influence of rapidly changing temperature and cross-gas effects, and a significant level of experience is required to apply the corrections needed to get useable real-time air quality data. At this stage there are two options: one is to try to deal with the challenge in the measurement hardware, such as managing the conditions in which the sensors operate, but this often leads to large and expensive hardware. The other option is smart cloud-based correction algorithms.
Because of the length of time it has been in the field and the huge variation in environments in which AQMesh has been used and validated / corrected, AQMesh is acknowledged through independent studies to be further down this route than any other small sensor system. Even smart city projects which aim to deliver ‘high level’ air quality information, such as ‘the air quality is better here than there’ or some traffic light system, need to be confident that such conclusions are correct if they are not to be challenged by local authorities and stakeholders.