The $100 CO2 monitors do not measure CO2, they measure VOCs, which in typical home and office settings closely correlates with CO2 (because humans emit both at a relatively constant rate and humans are the main sources of both in typical home and office settings).
Does this mean that a cheap “pseudo-capnometer” can be created which measures VOCs collected via a nasal cannula? Or would measuring VOCs instead of CO2 change the results at that level (but why?)?
There exist inexpensive real co2 sensors, e.g. https://www.sparkfun.com/products/22396 . Datasheet says only updates every 5 seconds & 60s response time “for achieving 63% of a respective step function”, which I guess is what parent comment means by “They’ll likely be extremely slow”.
Probably worth searching e.g. digikey for sensors with faster response time.
The $100 CO2 monitors do not measure CO2, they measure VOCs, which in typical home and office settings closely correlates with CO2 (because humans emit both at a relatively constant rate and humans are the main sources of both in typical home and office settings).
Does this mean that a cheap “pseudo-capnometer” can be created which measures VOCs collected via a nasal cannula? Or would measuring VOCs instead of CO2 change the results at that level (but why?)?
>Does this mean that a cheap “pseudo-capnometer” can be created which . . . ?
I doubt it, but don’t know for sure because I don’t know anything about the mechanisms by which people outgas the VOCs.
There exist inexpensive real co2 sensors, e.g. https://www.sparkfun.com/products/22396 . Datasheet says only updates every 5 seconds & 60s response time “for achieving 63% of a respective step function”, which I guess is what parent comment means by “They’ll likely be extremely slow”.
Probably worth searching e.g. digikey for sensors with faster response time.