i have a couple of no-name air quality sensors and they react to the environment fine, but they read high (like 500) CO2 outdoors. I got them in case CO2 was th

i have a couple of no-name air quality sensors and they react to the environment fine, but they read high (like 500) CO2 outdoors. I got them in case CO2 was the reason for my spouse's insomnia. I've tested them by putting them in a large bowl with dry ice, and it certainly reacts to that. Also cooking makes the AQI number change dramatically. right now the powered one says my AQI is 2, CO2 is 515, CO is 9, HCHO is 18, and TVOC is 0.2. Neither of mine mention temp or humidity, and i've never taken them apart. I certainly won't rely on them to tell me if i actually have TVOC or HCHO issues. And i wish they had SD card slots that stored the values, like my 8 remote temp/humidity sensors and their base station.