
Ask HN: Air Quality Monitor? - luckman212
Was visiting in-laws over the holidays and they had purchased this Dyson Air Purifier[0] which displays live AQI readings. It was an eye-opener because the air quality fluctuated pretty dramatically throughout the day based on what whether someone was frying something in the kitchen, or the windows were open, someone downstairs was smoking, etc.<p>Now I want to purchase a monitor for our small apartment, but after 3 hours of searching I haven&#x27;t found any that seem worth buying. I&#x27;m after something that will detect CO2, PM2.5, and VOCs. It should have some data logging&#x2F;alerting&#x2F;reporting capabilities as well either via Bluetooth or WiFi.<p>I&#x27;m aware of some models like Awair rev.2, AirVisual Pro aka &quot;Node&quot;, and uHoo, Netatmo, and Airthings. But all of them seem to suffer from either poor quality control, or wildly inaccurate sensors- to the point of being useless.<p>Anyone have a suggestion for a well-made, accurate sensor?<p>[0] https:&#x2F;&#x2F;www.dyson.com&#x2F;purifiers&#x2F;dyson-pure-cool-desk-white-silver.html
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mtmail
There's some background information about what sensors are used in a recent
reddit thread (it's about triggering an alert by farting, but the good content
is always in the comments). It left me with the impression even the Dyson
product is home use, not accurate scientific use.

[https://www.reddit.com/r/videos/comments/edsf4b/dyson_air_pu...](https://www.reddit.com/r/videos/comments/edsf4b/dyson_air_purifier_immediately_registering_my/fbkuxjt/)

"So I'm one of those fancy hazmat dudes with the EPA (On-Scene Coordinator).

This thing isn't reading VOCs. You need a photo ionization detector for that.
And methane, the primary compound in farts, can't be read by the majority of
PIDs. They usually are 10.6 eV lamps. Methane has a ionization potential of
12.6. What's required to read it would literally burn out when in contact with
oxygen within a month, if not sooner.

To properly read it you need a flame ionization detector. This uses hydrogen
to break about carbon-hydrogen bonds and has a equivalent to a 15.6 eV lamp.
They also cost over 12 grand."

~~~
luckman212
Interesting. Ok, let's forget about VOCs then, how about just an accurate
reading of PM1/2.5/10?

