Air Quality Shorts: Introduction & Readings

The Sensors and Science Behind The ESDK and Good Air Canary.

The Good Air Canary is powered by the ESDK (Environmental Sensor Dev Kit), which currently has a powerful array of Sensors - Temp/Humidity, VOC, CO2 and Particulate (PM1, 2.5, 4 & 10) - which give you a great overview of Air Quality. 50 of these kits have been given to Engineers around the world, and another 12 given to our 'AQ Influencers' who have made a wide range of projects in response to understanding what good air quality means to them.

This mini series follows-on from that work, and gives you an overview of what each of the sensors do, how they work, and how to incorporate them into your own air quality projects.

What Do The Readings All Mean?
From ppm or μg/m³, to AQ Indexes...here's the Primer:

If you have a phone weather app - you may have seen ‘AQI’ Index, as a measure of Air Quality ‘at a glance’ this is an amalgamation of a load of different Air Quality readings, and actually varies from country to country! It is not a globally standardised unit, but is nonetheless useful to gain a simple overview of the safety/hazard in your area.

However, if you wanted to know more about what each of the readings mean, either in specific APIs like the Met Office, etc. - you will need a basic understanding of what the ppm (parts per million) mean, and perhaps more importantly, what is ‘good’ or ‘bad’.

It also helps to have ‘context’ to the reading - for example, the background CO2 on Earth is around 420ppm. So if you have your AQ sensor outside, unless you are near a BBQ, it will not change much. Arguably it’s pretty redundant on a personal Outdoor AQ sensor. However, if you have a CO2 sensor indoors and are using it either as a Coronavirus ‘proxy’ (ie stale air --open windows, to reduce risk), or as a ‘good air’ alert (you work and sleep better if CO2 is below 1000ppm), then this is going to change a lot inside your home or office. To make the point - if CO2 outside jumped by 1000ppm, we’d probably all be dead, because the ecosystem inside your home is of course different to that of the entire world. So it depends on what you measure and what you want to know.

The Air Quality Shorts Series.

The following series will give you an overview of sensors of interest. Right now we have:

• Temp and Humidity (Heat and Moisture)
• VOC (smelly things)
• CO2 (Combustion/Respiration)
• Particulate (dusty things)

But stay tuned, as we also have more sensors in development! So follow this Article for updates...