I've been noticing how Simple Air Sensors ( #simple-air-sensor) will pick up fog from a humidifier, and have had a lot of success working with both adults and kids at events using a humidifier with these sensors. Because the #plantower sensor in the Simple Air Sensor (same as in the #purple-air) is triggered by fog, and because fog dissipates so quickly (and is safe to breathe), it's a really effective demonstration of the sensors reacting to the presence of a source of air "pollution" -- even though it's not really pollution.
It's interesting because people ask if it's because the fog droplets are in the 1-10 micron size range, and if that's what's causing it to detect them.
It's also really useful to show how the sensor has limitations -- that it can't tell the difference between a water droplet and a particle of air pollution.
Finally, the fog can be directed with a light breeze from a fan, and objects can even be placed in the path of the wind, shielding some sensors but not others. So with several different simple air sensors, you can kind of roughly simulate (at a small scale) the dispersion of an air pollutant in a real-world environment.
I'm interested in how this could be useful for any of the following:
- planning the placement of sensors on a site
- running a group activity to train people in placing sensors, whether this type or more expensive ones
- discussing the limitations of different types of sensors
- discussing how airflow affects readings
Finally, I was interested in getting some Simple Air sensors to run with a running average over 1 minute, rather than reporting every second -- to help demonstrate how some sensors only give the aggregate reading over a period, and so can miss moments of high pollution.
What do folks think of all this? Ideas or feedback? Thank you!