Do-it-yourself Air Quality Monitoring

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Our air speaks to the internet. Air Quality Egg base stations glow different colors as they feed NO2 and CO data into the Clean Air Council router.

Our Air Quality eggs have arrived! Wait, what’s that?

Earlier in 2012, Clean Air Council donated to #airqualityegg’s kickstarter campaign, a small group of DIY designers, engineers, computer nerds, etc. that decided to make an open-sourced do-it-yourself air quality monitor. Working on an air monitoring campaign in Philadelphia, we understand the need for inexpensive and openly available methods for everyday folks to understand the quality of the air around them.

We put two eggs up in our office: poached is currently perched on the ledge outside our third floor office window in the Rittenhouse neighborhood of Philadelphia; over-easy is inside the office, humming away next to my co-worker’s desk. Those links in our cute egg names will connect you to the live feed of air quality data for each of our eggs. If you’d like some historical data from our monitors click on poached or over-easy and it will take you to the historical and live feeds for each.

over-easy looks out over the Philadelphia skyline as it broadcasts our air quality data over the internet.

over-easy looks out over the Philadelphia skyline as it broadcasts our air quality data over the internet.

Our previous air monitoring projects have involved some combination of measuring particulate matter below 2.5 micrometers and black carbon, a type of particulate. We’ve borrowed equipment for these monitors and used them in discrete monitoring deployments in Port Richmond, but as an environmental organization these types of air monitors are usually outside our budget and data analysis expertise. Other environmental organizations and concerned citizens have used DIY air sampling–via the bucket brigade–to test for elevated levels of dangerous gases with huge successes in creating new regulations on offending facilities.

In Port Richmond, though, we aren’t testing for unexpected spikes in levels of dangerous gases, but are instead measuring the more persistent release of particulates into the local atmosphere. While some events like explosions and massive fires will induce a spike in particulates, our real concern is the long-term elevated levels of particulate matter produced by, say, automobile traffic or diesel-powered industrial operations. Cities, then, tend to have higher long-term concentrations.

We’d love for our eggs to measure particulate matter, and I think our DIY developers are working in this direction, but they currently measure CO (carbon monoxide) and NO2 (nitrogen dioxide). In urban areas, CO is primarily produced by automobiles and can serve as an indicator of the amount of traffic present in the immediate environment. Its health implications are immediate, in that it reduced the amount of oxygen available to your organs. Similarly, NO2 is produced by combustion from vehicles. It has its own effects on your health, primarily related to respiratory illnesses. It is also a precursor to forming ground-level ozone and particulate matter, both having more serious health risks ranging from asthma to cancer.

The U.S. Environmental Protection Agency regulates the ambient levels of each of these pollutants and sets their  national standards. For CO, the one-hour national standard is 35 parts per million (ppm) and for NO2 it is 100 parts per billion (ppb). As these are do-it-yourself sensors, though, they don’t have the accuracy that more expensive monitors do. The air quality egg community has been  back and forth about the reliability of the measurements and there are some useful debates buried in the googlegroup on this subject. Unfortunately, poached is currently reading levels that are negative (!) for NO2 and our CO levels are about three times the national hourly standard. We’re staying unalarmed in this office, anticipating that there will be some growing pangs in developing affordable and mobile air quality monitors. We’ll spend some time tinkering with them (we already unplugged and plugged back in) and see if anything changes. Until then, we’re looking forward to  opening and shutting windows, noting urban traffic patterns, and paying close attention to changes in our eggs data output, which, will hopefully mean something in the near future.

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poached, tipped over but still feeding data to the base station.



  1. this is awesome! I need check these babies out!!! (p.s. blog looks great but the links are indicated only by a very fine grey line under the word, it’s too tough to see where the links are) 🙂

  2. Peter de Vries said:

    I found an even more interesting project. The Smart Citizen kit.
    With more sensors, a self-powered solution using a solar panel and a very rapidly growing userbase. Check it at Kickstarter

    They have already a very professional and visualy stunning website at: Smart Citizen

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