UWSojourner:
Do any RBs have CO2 detection?
From what I've read they don't. There seem to be small detection devices out there, why nothing adapted to RBs yet?
UWS, I just reread the TDS thread whose link was posted above.
Not much has changed yet, I'm afraid.
The two rebreathers announced back then that deploy heat sensors, the APD Evolution and OMG Nemesis, have yet to enter the civilian market. Neither actually measures the CO2 content of the loop, but rather the "temperature front" of the most active sorb as it moves through the scrubber bed, indicating how much of the absorbant has been spent. How that will pick up on channeling still eludes me, so I still consider it an indicator rather than a monitor.
The elusive Infinito does have actual CO2 sensor technology that measures loop content of CO2, but is currently not available to the public and also prohibitively priced for many divers (reportedly around $18,000).
The technology could be available as a complete aftermarket controller system, but how feasible would it be to produce a deco/CO2 integrated controller that would be available for $8,000+ ... .
Micropore, manufacturer of the ExtendAir cartridge, released the following data for it in form of a graph. The CO2 concentration in the loop reaches 0.5% at about 210 minutes. Testing was performed at 40 RMV, 1.35 LPM CO2 injection, 1 ata and 13 degrees C/55.4 degrees F. That's for the Dolphin/Azmuth cartridge, where quite some exhaled gas is vented before the scrubber. And 1 ata is of course nonsense unless you dive in your bath tub.
Maybe the most important post in the thread is the one by Stuart McLean (#28), I wholeheartedly agree with him on that issue.
Handle your absorbant properly, pack your correctly, be vigilant with your pre-dive and pre-breathing, and stay within manufacturers ratings and you shouldn't need a monitor.
For the thousands of dollars you safe over a half-a$$ed indicator, and twice that over an accurate monitor you can buy a lot of sorb and afford not to exceed the manufacturer's ratings.