A Smart Approach to Air Quality: Monitoring and visualising
Midlands NHS Trust collaborates with South Coast Science on new Air Quality Monitoring Project
When selecting an air quality monitor, most non-specialists find it a challenge to understand what distinguishes one product from another. Those in the industry, environmental scientists, manufacturers and suppliers, know what questions to ask and what to look for. For non-specialists, one grey box looks very much like another and what goes on inside the monitor is less understood.
Yet, understanding the different product design choices made by air quality monitor manufacturers is essential for
- calculating the lifetime cost of the device
- understanding power consumption of the monitor
- understanding manufacturer’s accuracy claims
Small design details make a big difference
Many commercial air quality monitors heat the air prior to sampling, as this reduces the impact of fluctuating temperature and humidity. This is important as the sensors used are sensitive to these changes that naturally occur outdoors. Heating the air beforehand reduces this problem. At the same time, it creates other design requirements.
The air must be pumped into the device in order to be heated and the monitor uses more energy both for the heater and for the pump. Filters are also needed to protect this mechanism and must be replaced quarterly, which require site visits and a subsequent increase in maintenance costs for the end customer.
South Coast Science has developed a more elegant solution to the problem that saves on maintenance costs, whilst improving data accuracy. Praxis monitors use machine learning to make dynamic corrections for temperature and relative humidity (on the device). This removes the need for pumps, heaters and filters, resulting in a monitor that is both smaller and less expensive to run.
MCERTS: Independently validated data (and beyond)
Whatever the other design choices, little else about the monitor matters if its data cannot be relied upon. So how can the end-user be confident of data accuracy? They need to see independent validation, which is why South Coast Science successfully undertook MCERTS certification for particulate monitoring. The Praxis/Urban is now certified, with the Praxis/Cube to follow shortly.
MCERTS is a formal product certification scheme that operates according to the Environmental Agency’s performance standards. This means a recognised third-party has verified the equipment provides reliable monitoring data that meets UK and international regulations.
However, for South Coast Science that is not enough. Our goal is ‘equivalence’, that is, data of the same quality as that from reference devices as used by the government to report background air quality nationally.