3 ms·

I have a MH-Z19C and have been running it with auto-calibration disabled for over a year and it didn't drift much. Is is possible that you have auto-cal on and

I have a MH-Z19C and have been running it with auto-calibration disabled for over a year and it didn't drift much. Is is possible that you have auto-cal on and the sensor is never exposed to true outside air? It uses some sort of minimum tracking to calibrate the ~400ppm point. This is anecdata though.

wkat4242 4y ago
Exactly I'm pretty sure this is what it is. It won't drift much but you do have to turn the auto calibration off, otherwise it will grab any low CO2 moment and try to calibrate to it, drifting further off track with every calibration.