CO2 sensor wildly varies

Hi, I bought several AirGradients and I’m seeing wildly varying values in the CO2 in a few rooms.

I flashed them all to run ESPHome to connect to Home Assistant and I’m graphing the values with Grafana.

Especially the red (office) shot up for no reason and is now constantly reading values of 1600, even when the room is unoccupied. And other sensors are dipping below 400ppm which is basically impossible.

Anyone know what’s going on? I attached a graph of my CO2 values.

The SenseAir S8 has an accuracy of ±70 ppm ±3% so it can dip below 400ppm.

For the high one, I would recommend you observe it for a week. The automatic baseline calibration should kick in and step by step calibrate it down.

Was the monitor exposed to strong vibrations or moved around? We have seen these very high levels when the sensor fell down and that made it completely off but it recovered through the automatic baseline calibration.

Got it - will observe for another week and check in then. The monitor was not exposed to any strong vibrations or movement. It was probably unplugged and plugged in again around the time of the spike.

Unplugging it should not cause this.