> Do you think it a coïncidence that most spy satellites are launched from Vandenberg?
It's not a coincidence, it's geography.
It is desirable for reconnaissance satellites to cover the entire planet regularly. That means high inclination orbits. That means southward launches (as opposed to eastward). That requires a launch site with ideally lots of ocean and not a lot of population to the south/southeast.
The US does plenty of military launches into other orbits from the east coast.
You should be using the newer version, MH-Z19B, not MH-Z19.
The protocol is compatible though.
Also note they come in up-to-3000ppm and up-to-5000ppm variants. Be sure to get the latter.
In case it helps anyone: a very fast way to get it working and get graphs is to connect it to a Raspberry Pi running HomeAssistant. Takes a few clicks and 3 lines of config.
I agree, I've measured this as well. Window in adjacent room (with open door between rooms), window opened 5-10cm, CO2 level stays pretty much down.
I've also found that when all windows are closed, an air purifier seems to help (or a fan, lowest level is fine). Obviously it doesn't remove the CO2, but it seems to prevent buildup in the one corner where you are (bed, desk). I'm sceptical it's a problem but the data shows it is.
It's not a coincidence, it's geography.
It is desirable for reconnaissance satellites to cover the entire planet regularly. That means high inclination orbits. That means southward launches (as opposed to eastward). That requires a launch site with ideally lots of ocean and not a lot of population to the south/southeast.
The US does plenty of military launches into other orbits from the east coast.