Looking at the spec sheets; (which I am sure all have read, just included here for sake of completeness)
http://www.winsen-sensor.com/d/files/PDF...Ver1.0.pdf
http://www.winsen-sensor.com/d/files/inf...ver1_0.pdf
the modules seem to be able to measure from 0-2000ppm (a minimum of 0ppm) rather than a minimum of 400ppm. 400ppm being the point at which they are calibrated. (if a "B" model then self calibrates every 24 hours, Automatic Baseline Correction ) and 327199; https://thingspeak.com/channels/327199 regularly reads below 400ppm most days. It seems as if 327199 has the most realistic diurnal range of 390ppm to 490ppm. Why is this so different to the rest of us is worth asking. Hornychz??
Both sensors seem to be able to measure a bigger range of 0-5000ppm, quite how this is decided I am not sure; but I am sure Werk has built this decision into the code if that is the way the range decision is made.
http://www.winsen-sensor.com/d/files/PDF...Ver1.0.pdf
http://www.winsen-sensor.com/d/files/inf...ver1_0.pdf
the modules seem to be able to measure from 0-2000ppm (a minimum of 0ppm) rather than a minimum of 400ppm. 400ppm being the point at which they are calibrated. (if a "B" model then self calibrates every 24 hours, Automatic Baseline Correction ) and 327199; https://thingspeak.com/channels/327199 regularly reads below 400ppm most days. It seems as if 327199 has the most realistic diurnal range of 390ppm to 490ppm. Why is this so different to the rest of us is worth asking. Hornychz??
Both sensors seem to be able to measure a bigger range of 0-5000ppm, quite how this is decided I am not sure; but I am sure Werk has built this decision into the code if that is the way the range decision is made.