I have two different air quality monitors now (QingPing for home, Aranet for the road) and the CO2 readings tend to diverge, sometimes a lot. Why… is this, as in technical details?
@astrokatie.com@kateviolette.com this seems like the kind of thing you might know
possibly relevant note: the QingPing has never been calibrated manually and I may or may not have done that with the Aranet at some point a long time ago
Maybe you've already done this, but I know for the Aranet, it can use recalibration every once in a while (like on the order of 6-12 months if I recall correctly from the manual). I'm less familiar with the QingPing but I wouldn't be surprised if it also could use recalibration sometimes.
I'm not super up on the technical details of why they need recalibration, other than that measuring molecules in gas form is a subtle exercise in general.
(e.g. I have a cool breath monitor for gut issues, and the app will yell at you if you're blowing too fast or slow bc it can bork measurement)
I was just reading the directions to take a new-to-me brand of COVID test and was struck by how many steps had “if you bork this, you’re more likely to get a false negative” disclaimer on them.
Oh wow
"In the case of automatic calibration mode, the Aranet4 device needs to be exposed to fresh air at around 420 ppm (for instance, outdoors or in a room with good air exchange) for approximately 8 hours during each 30 day operation period"
And 30m sitting outside for manual calibration
FWIW last year I bought 4 Aranets for an event and they differed in a range of up to 60ppm before I calibrated them all... Then they were generally 15ppm or less apart.
I have a pocket CO2 monitor that needs to be calibrated something ridiculous ike once a week. It tries to recalibtate itaelf, and sknce it's never outdoors, it loses track of what normal is
I haven't looked at the technical docs for these yet but CO2 detection often uses an infrared component and localized heat sources can skew the readings (sunlight, near a cooktop, body heat, near a heat vent etc).
