As part of our aim to monitor and improve Air Quality in Chippenham we’ve launched a beta Environmental Dashboard with a live feed of PM10 and PM2.5 particulate readings.
This is a low cost citizen science project using the £75 Enviro Urban Raspberry Pi Pico W board and Stevenson Screen from Pimoroni.
The PMSA003 sensor used by Pimoroni has been shown to exhibit good correlation with many times more expensive calibrated sensors in field trials as shown in this paper. The main caveat being that at relative humidity levels greater than 75% the sensor has been shown to read high with an error up to +15%. Hence the Environmental dashboard displays relative humidity next to the Particulate matter readings for correlation.
The board is battery powered and mounted in a Stevenson Screen. As well as PM 1, PM 10 and PM 2.5 particulate monitoring it records, temperature, pressure, Relative humidity and noise.
Readings are taken automatically every 15 minutes and uploaded to a cloud server once per hour. In between the board goes to deep sleep allowing the batteries to last many months.
The readings are uploaded to an Adafruit.io cloud server and a live dashboard has been created presenting the last 30 days of data.
The monitor is situated in a front garden in Langley Road, Chippenham; a busy main road, but certainly not the busiest in Chippenham
There are some limitations to this project as might be expected with such a low cost monitor, namely it is uncalibrated. We are still hoping to revive our original Air Quality project using more expensive calibrated sensors, that could subsequently be used as an evidence base for policy. If you have the energy to get involved and lead that project please contact us?
You can find out more about our Air Quality projects on our web page here
You can see our beta Environmental Dashboard on our Adafruit.io page here