[Chris] has allergies, asthma, and uses a wood burning stove. You can imagine why testing his air quality might be something he’d be interested in. He has a very nice $290 laser particle counter, but was really curious how the $12 sharp sensor he found would stack up. To find out, he plugged it into an arduino and started logging both on pachube.
After a few different tests, like lighting a match, blowing it out, and letting the smoke flow into the sensors, he decided he needed something better. Cooking some pancakes turned out to be his ultimate method. After charting the dissipation of particles after cooking a nice batch of griddle cakes, he found the two sensors to be surprisingly similar.
This gives me some ideas for at home. Both my fiance and I have allergies and this would interesting to see the air quality at home.
This makes me want pancakes 🙂
There is currently a project going on at CMU which entails persontal tracking of environmental parameters, which also encompasses air quality monitoring.
http://bodytrack.org/
It turns out that the air quality in the average home is absolutely terrible, more so for city living. We’ve tested a few of these sensors and found the sensitivity to be very poor (they only work particularly well in the case of high particulate concentrations) so we’ve focused more on laser-based particle detection. On average, you’ll see proportionally higher concentrations of particles at 2.5 micron and below, which this sensor does not do well with.
Still, it’s very promising to see others taking an active interest in air quality. Nicely done!
I got the $15.50 Shinyei Dust sensor (http://www.seeedstudio.com/depot/
grove-dust-sensor-p-1050.html) hooked up to the Arduino last night
and got it posting to Pachube (https://pachube.com/feeds/56469)
The interface is digital and pretty simple (you calculate the ratio of
how long the I/O pulses are low compared to high over 30 seconds).
The Shinyei looks much more promising for cheap processors like the
Arduino. I didn’t have to deal with the quality of the A/D converter
or additional circuitry. Time will tell, but it looks like I have more
correlation at lower particle concentrations.
That many wire nuts is bound to attract squirrels.
Just as note: The DC1100 Pro Air Quality is actually a really cheap particle counter that did piss off many manufactors.
This is why I try to cook and fry outdoors whenever possible. Frying, dirty ovens and stovetop burners are the biggest source of indoor air pollution, sans smoking.
This makes me wonder what it would take to build a laser based particulate sensor.
What does it take?
Probably laser, some kind of photo sensor, micro controller and fan or some other means to get air into sensor but also a lot of knowledge.
The last one is probably the main obstacle.
Combining asthma and allergies with wood burning is a really bad idea.
http://www.samharris.org/blog/item/the-fireplace-delusion