How we monitor Air Quality

We monitor Air Quality using a combination of automatic monitoring stations, which you can see on the map on this site.  Each of these stations records the levels of pollutants in the area surrounding it.  You can see what the machines are recording for example this is the monitoring station information for Oxford Centre

We also use diffusion tubes which are placed around the county.  These monitor pollutants manually and are checked at regular intervals to allow us to gather data from them.  

Monitoring Passive diffusion tube. This is a simple and relatively inexpensive device consisting of a plastic tube which can be attached to street furniture (e.g. a street light) allowing a sample of air to be collected (over a recorded exposure period) by diffusion into the sampler. The tubes are sealed and then sent off for quantitative analysis. They give a good general indication of average pollutant levels.

air quality monitoring diffusion tube

Automatic real-time monitor. This produces high-resolution measurements over short averaging period e.g. 15 minutes. The air sample is analysed on-line and in real-time. This method offers continuous data, which identifies peaks and troughs during a short period e.g. 24 hours

automatic air quality monitoring station

Combining these methods gives us a huge amount of data to understand what is happening with the Air Quality throughout the year.  Explore the rest of this section for more detail on the pollutants and the policies that govern how Air Quality is monitored.