[andreyf]

after a bunch of looking, the paper that had the most detail on quality and sensors used is https://www.sciencedirect.com/science/article/pii/S036013232...!

the most accurate readily available for CO2 seems to be the "Laser Egg+ CO2" for $200 https://shop-usa.kaiterra.com/collections/frontpage/products... which uses SenseAir S8 but looks and sounds a little silly

and the $150 "Awair Element" https://wiki.liutyi.info/display/CO2/Awair+Element+inside which uses the Amphenol Telaire T6703-5K