the new sensor is now reading lower (in quite close proximity to each other but bit more airy box on the new sensor…)
old sensor
2018-02-06,19:39:46,18.2,C,1010.1,hPa,49.4,%RH,83078,Ohms
2018-02-06,19:44:47,18.2,C,1010.2,hPa,49.4,%RH,83366,Ohms
2018-02-06,19:49:48,18.2,C,1010.1,hPa,49.2,%RH,83164,Ohms
2018-02-06,19:49:48,18.2,C,1010.1,hPa,49.2,%RH,83164,Ohms
new sensor
2018-02-06,19:37:14,18.4,C,1009.5,hPa,47.0,%RH,67781,Ohms
2018-02-06,19:42:15,18.4,C,1009.6,hPa,46.8,%RH,67535,Ohms
2018-02-06,19:47:15,18.3,C,1009.6,hPa,47.0,%RH,68111,Ohms
2018-02-06,19:52:16,18.2,C,1009.6,hPa,47.0,%RH,67508,Ohms
but then, I suspect as the new sensor has not been outside when air quality was in the 400,000 range (very good) it is relative to it’s highest reading…
stm sensor got all the logic you would have to manually code for one of those expensive wand co2 sensors which need exposing to an absolute minimum co2 level (somewhere outside in the cundry when they have not been spreading pig poop probably) value to calibrate…