How To Smell Pollutants

Step 5 Build Away!

Without burning in this circuit for a week and adding a thermistor, this is really only good for reading relative concentrations of chemicals: eg, if you want a 'lower-VOC' paint, you could hold this over different open bottles of paint (in a room of constant temperature) and reasonably feel a bit safer using the paint that registers the lowest value. Obviously, there are nasties (and probably some VOCs: I don't know) that this doesn't detect, but it's definitely a bit better than nothing:-)

Attached is a pdf Figaro Sensors provided, detailing the response of thermistors at different temperatures. Definitely not the only thermistor you can use, but may be useful as you explore your own, better version of this project.

A cool expansion I want to see is to display the approximate level in parts per million (ppm) of air pollution on my back as I ride my bike through traffic, maybe with an LED 'Mr. Yuck' sign that turns on above a certain concentration as well. Let me know what you build, and have fun!