CO2 bricklet not working correctly

[Wailer]

Hi,

I have a tinkerforge weather station to which I added a CO2 bricklet, among other sensors. Recently, the CO2 bricklet has started displaying inaccurate values, sometimes dropping to 0 ppm, even though the minimum reading should be around 400 ppm. Do you have any idea what might be causing this issue? Should I consider replacing the bricklet?

[borg]

As far as i understand how the CO2 sensor we use works, it should automatically recalibrate itself to ~400PPM after some time:

Zitat

The automatic self-calibration (ASC) algorithm autonomously generates a reference value by analyzing the measured CO2 concentration over a period of time.

The correct application of ASC requires the SCD30 to be regularly exposed to air with CO2 concentration = 400 ppm, as is the case in well ventilated buildings over night without human presence.

So when the sensor sees a specific PPM concentration regularly, it will calibrate itself towards this value being 400 PPM.

[Wailer]

Yes, it used to calibrate to 400 ppm and it didn't drop below that. But now it drops to 0 ppm. It's been like that for weeks. Note that the values still vary in a meaningful manner, but the minimum value is now 0 ppm rather than 400 ppm.

Edited September 11, 2024 at 08:54 AM by Wailer

[borg]

Strange. Have you tried turning it off for a a few hours and then on again?

[Wailer]

Yes, I did and it's still the same.