Exhaled CO2 tracking with capnometers

Agaricus mentioning the existence of a consumer-level CO2 tracking product made me realize that there might be others interested in tracking their levels. I’d be curious to hear from anyone that’s tried it.

Here’s a list of capnometers I’ve found so far. The prices range from pretty-high to “this thing is meant to be used in a hospital.”


  • Product page: Android / iOS
  • Price: $350. Sensor cost works out to $5 a session. Sensor expiration is >1 year.
  • Data: bluetooth sync to mobile app. Reports a TEE after a breathing session. I think there might be a hidden way of getting the raw data, or at least more-detailed numbers used for the TEE calculation.
  • Accuracy: probably very accurate.

Carbogenetics Capnometer
(made by an online acquaintance of mine, but I have no connection/affiliation with it)

  • Product page
  • Price: $407
  • Data: tracked on their web site (I don’t see a readout in the pictures, though I assume there must be a display or bluetooth connection for setting up wifi)
  • Accuracy: ?

Masimo EMMA “Emergency” Capnograph

  • Product page
  • Spec sheet
  • Price: ~$2200
  • Data: readout displayed on device with a minimal graph. No logging?
  • Accuracy: +/- 2 mmHg, +/- 0.3 kPa

Masimo EMMA “Mainstream” Capnometer

  • Product page
  • Spec sheet
  • Price: ~$1600
  • Data: readout displayed on device. No logging.
  • Accuracy: +/- 2 mmHg, +/- 0.3 kPa

Smiths Medical Capnocheck II
(they have other models, but this one seems the most appropriate for self-experimentation)

  • Product page
  • Price: ~$1600.
  • Data: readout displayed on device. Can “infrared print”. Unsure whether you can dig back into “logs”.
  • Accuracy: ?

I’m curious about the sensor lifetime. Breezing’s are one-time use, and while Masimo doesn’t mention a lifetime on theirs, they say “no routine calibration required.”


Can any of these be connected to TerraPass, so you can purchase carbon offsets automatically? :slight_smile:

Never fear, I make it a policy to only exhale indoors, thus keeping the CO2 sequestered :slight_smile: