This reads like a disguised ad for AirGradient, which pops up here every now and then. I fell for it because it claimed to be "open". Well, although it is definitely more "open" than most, it feels like an afterthought.<p>See for example this: <a href="https://forum.airgradient.com/t/airgradient-diy-pro-pcb-3-7-2-4-1-2023-04-13-source-code-sketch/927/13" rel="nofollow noreferrer">https://forum.airgradient.com/t/airgradient-diy-pro-pcb-3-7-...</a>, linked to a Github issue opened in June.<p>Somehow, the source code for the new version has been overwritten by an older (CC-BY-NC) version, yet the issue has been left to rot, both on the support forum and on Github, letting me to think that the "openness" is mostly a posture to lure the HN crowd. Additionally, the -NC clause is definitely a deal breaker, and I should have investigated further before giving them my money.<p>(it sucks to air it out in public here, but apparently the AirGradient folks don't care much about issues raised on their own forum).
Author here. I'm planning to do some more comparison testing of PM modules and planning to benchmark modules from Sensirion, Plantower, Cubic and AlphaSense. Let me know if you know some other sensor modules that could be interesting. I think this could be a pretty interesting follow up post.
I’ve gone down the air quality monitor rabbit hole and, after building my own, have settle on just buying/recommending the Awair Element.[1]<p>Interestingly, it’s not in the table in this article.<p>[1] <a href="https://www.getawair.com/products/element" rel="nofollow noreferrer">https://www.getawair.com/products/element</a>
This is common.<p>Bluetooth headsets? There are only a handful of chipsets in all.<p>A to D converters? Same.<p>On and on. There are often not more than a handful of options for many ics.
I like the Dylos laser particle counter:<p><a href="http://dylosproducts.com/dc1100paqmc.html" rel="nofollow noreferrer">http://dylosproducts.com/dc1100paqmc.html</a><p>The version I have has an RS-232 output and a graphing program that runs on Windows. Connect it to an old laptop with an FTDI USB to RS-232 cable and you can log particle count histories. You have to clear the air intake port of dust once in a long while with a burst of compressed air.<p>The Sharp LED dust sensors aren't as accurate as a laser counter, but can give you a useful enough readout for dust and smoke:<p><a href="https://global.sharp/products/device/lineup/selection/opto/dust/index.html" rel="nofollow noreferrer">https://global.sharp/products/device/lineup/selection/opto/d...</a><p>These are probably what is in the cheapest air quality monitors.
During the pandemic I took 2 clear tubes, and put PM meters in them. I used tape to tape various COVID masks between them and to seal them kind of air tight. Then I placed computer fans at each end to push air through. I learned that the best filters I could get only worked down to 2.5 microns.
At the point where you spend >$400 you might as well buy hardware to purify the air... Unless you have a very specific molecule in mind, a standard HEPA + carbon filter will fix 99% of your problem.
why do we have to keep suffering these AurGradient ads? the sensor itself is not close to being the whole story. as evidenced by the price range of the complete products built around said sensors.
Does anyone with an AQI sensor in their house actually use it to control HVAC equipment, or is it just for monitoring? In a commercial HVAC control system, if the AQI sensor (or CO2/NO2) reaches [setpoint], a make-up air unit and exhaust fan (or similar setup, could be an exhaust fan and outside air damper) will turn on until the AQI value is below the setpoint. Is anyone using an AQI sensor to energize a relay coil to turn on their furnace fan to try and correct PM2.5 and CO2 levels?
This is the best one I've seen: <a href="https://boseansafety.com/products/air-quality-monitor-home-t-z01" rel="nofollow noreferrer">https://boseansafety.com/products/air-quality-monitor-home-t...</a><p>It's by an industrial mining supply company instead of a consumer goods company, and seems to be more accurate than the cheap Amazon options I tried.
It would be nice to add radon to the table. Some consumer air quality monitor have it and the usability of the mail test means many people don't know their exposure.