I'm often personally going on Zoom call with customers to make sure they get 100% out of the monitor and address these types of questions. Please send me a note through our support form and I'm happy to help [1]. Please make a note in the support ticket to this link so that it will get assigned right to me.
Now regarding the CO2 sensor. We use the SenseAir S8 which is one of the best NDIR sensors out there. If you do not like the auto calibration, you can now switch this off in the dashboard or change the automatic baseline calibration to longer periods. To do this, go to Place Settings, General Place Settings.
In case you still have these wild swings, contact our support with your sensor ID and we will have a look.
Regarding VOC, this has also recently addressed and you can now change the learning gain offset to make it more behave like an absolute sensor. We clearly describe the behavior of the VOC sensor on our website and this is actually the behavior of all newer generations of VOC sensors. We use the Sensirion SGP41 which is regarded one of the best ones.
Now, you are free to call it a "useless piece" but I'd appreciate if we keep the discussion fact based. As far as I know, there is no other air quality monitor in the same price range that is substantially better than ours.
Measuring air quality pollutants is not as simple as measuring temperature so there are inherent shortcoming in some of them. It is part of our mission to educate people on these. This is why we published for example the air quality cheatsheet. [2]
I bought a pair of sensors based on the HN mentions, and so far I'm pretty happy. I was mainly interested in their PM sensor, which isn't on your list of complaints, and works quite well.
I discovered my rangehood, which doesn't have an outdoor exhaust, is even more useless than I had imagined. I bought a HEPA filter for my kitchen to run while I'm cooking (a Blueair based on other HN comments) and based on the PM sensor readings of the AirGradient the HEPA filter is quite effective.
I did have to configure the COâ‚‚ sensor recalibration period to keep the numbers sensible. It wasn't so easy to set different recalibration periods for the indoor and outdoor sensors, but with some curl commands, I was able to get things configured to my liking. I do appreciate that, in principle, I can edit the firmware to my liking in the future.
The CO2 sensor does not read CO2 levels, and recalibrates automagically. I have completely wacky readings from it, from 200ppm to 2000ppm.
The VOC sensor also apparently does not read VOC levels, see discussion here: https://forum.airgradient.com/t/measurement-values-for-the-a....
All in all, I'm frustrated I fell for the regular free advertising they get on HN.