CO2 and all other air quality indexers have to be very carefully calibrated regularly. It's not some slop you can just throw into a consoomer cheap iot device.
Article author completely ignores this for the obvious reasons.
Article author completely ignores this for the obvious reasons.
A sensor mounted in the office will get calibrated every night when the office is empty.
But close enough for most purposes. We aren’t doing laboratory measurements here, I just want to know whether or not to open a window.
What I do at home is I have multiple meters bought over the years, not all at once. If one of them is too deviated, I can replace it, but this deviation has never happened in the last five years. It did happen once about ten years ago with an old model.