Question Running a rebreather on only dilluent

[Gone for diving]

Can anyone tell me what is the difference that something gets labeled a gas extender vs SCR.

As far as I can understand they are identical...... maybe one doesn't have po2 sensors????
Or one dumps more gas???

 

[Wibble]

They're the same thing.

SCRs come in manual and electronic versions.

Manual ones leak at a constant rate and inject based upon pressure. Electronic ones monitor PPO2 and should be more frugal with gas consumption.

 

[Capt Jim Wyatt]

Lots of good discussion here. I tend to agree teaching SCR mode in an entry level/no deco/no overhead situation unnecessarily complicates things because bailing out to Open Circuit is the best, quickest and safest option.

Being able to use SCR mode in a cave environment is critical and must be taught and the student must master this skill.

I dive double LP85s in the cave. Tanks are generally filled to around 3500 psi which is about 220 cubic feet of gas. (35*6.4) If I switch to SCR mode and use a four-breath cycle while diving SCR mode I turn those 220 cubic feet into 880 cubic feet, essentially a "Gas Extender".