Diving Hyperb Med
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Comparative Study
The duration of two carbon dioxide absorbents in a closed-circuit rebreather diving system.
Diving rebreathers use canisters containing sodalime preparations to remove carbon dioxide (CO₂) from the expired gas. These preparations have a limited absorptive capacity and therefore may limit dive duration. The Inspiration™ rebreather is designed for use with Sofnolime 797™ but some divers use Spherasorb™ as an alternative. There are no published data comparing the CO2-absorbing efficacy of these sodalime preparations in an Inspiration rebreather. ⋯ Under conditions simulating work at 6 MET during use of an Inspiration rebreather a canister packed with Spherasorb reached CO₂ breakthrough 32% earlier with 10% less mass than Sofnolime packed to similar volume. Divers cannot alternate between these two preparations and expect the same endurance.