Eightlines Creations

Experiments in Physical Computing

Air Quality Monitoring

Recently I had a discussion with someone from the South Riverdale Community Health Centre on Air Quality monitoring in Ontario (AQI). I learned a number of things, there are only 40 Air Quality Monitors in Ontario and they test for six key indexes. Toronto runs a slightly different test, the Air Quality Health Index (AQHI) which is a pilot programme and reports on how the Air Quality will affect your health. The AQHI test for three key indicators. Detecting three indexes sounds pretty reasonable.

Mobile Air Quality MonitorBy building my own Air Quality project I hope to be able to reproduce the AQHI results at a fraction of the price and provide instruction to enable anyone across the province a chance to build their own.

To the left is a photo of the final (but always in a state of flux) result. It is a GPS enabled device powered by two AA’s which senses Air Quality and Ozone. I am currently running tests in a variety of ways. This is a more complex setup than it has to be. Below I’ll detail both a simple setup and a complex setup.

Simple Air Quality Monitor:

Connect the sensors as illustrated on the Wiring.org website. Attach to a computer and upload the data to a provider such as Pachube to share with the world. (Need an invite? Message me.)

Mobile Air Quality Monitor:

  • Arduino (~$45)
  • GPS Sheild ($16)
  • GPS ($60)
  • SD-Card ($20-60 depending on size - the SD-Card library uses a FAT-16 environment, so 1GB is all you’re going to need)
  • MintyBoost ($20 - 12 Hour lifespan for 2 AAs, 3 for a 9V battery)
  • Air Quality & Ozone Sensor ($6 each, see above for links)
  • Batteries (~$5 - I’d suggest rechargables)
  • 2 Resistors ($.15)

See above for the sensor connection details, then download the code to run the GPS and log the data (plus sensor data). I’m using the GPS CSV logging sketch.

Now for the notes:

  • I have no idea if this is capale of producing valid AQHI data, I’m researching this now.
  • The sensors are not calibrated, the data should only be valid relative to my own readings. I’d like to make the result reproducible across all sorts of devices.
  • Particulates are not being measured. Someone suggested taking apart a smoke alarm to dig out the sensor. I still have to try this.
  • Mapping of my results is coming soon. I intend on using this device in a setting where I can measure the effects on a highway with and without cars in the coming days. I will post the results.

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