ReBreather Charts & Pressure Groups

[www.scubamazing.com]

What are some of the different charts you use to calculate Nitrogen Absorption for re-breathers? I'm assuming you can't just use the standard Padi or Navy Chart.

 

[caveseeker7]

Depends on the type of rebreather being used.

On semi-closed units which use pre-mixed nitrox (or trimix) normal nitrox or trimix tables (fO2) apply. As the loop content isn't exactly the same as the supply gas you usually have to knock a couple of % off. How much depends on the type of SCR and the diver's metabolism.

For mixed gas CCRs that keep a setpoint (and hence change the mix during the dive) there are pO2 tables available. IANTD offers tables based on VPM (only for setpoint 1.2 ata I believe) and NAUI offers tables based on RGBM.

There are also several software programs that allow to cut your own tables for both fO2 and pO2 based on anything from straight Bühlmann to Pyle stops, G/F, VPM and RGBM.

 

[Mr.X]

What are some of the different charts you use to calculate Nitrogen Absorption for re-breathers? I'm assuming you can't just use the standard Padi or Navy Chart.

You could awkwardly use a PADI dial-a-bends wheel or a Navy chart if you are using air as a diluent in CCR. Better to use a nitrox, or tri mix PO2 chart used in any technical nitrox or tri mix class. Most CCR users opt for computer programs. Lot of tables out there for rebreather. There are some freebie CCR programs out there.

X

 

[wedivebc]

You could awkwardly use a PADI dial-a-bends wheel or a Navy chart

Ah but if you use it with a CCR unit is it still a dial-a-bend?
I have in the absence of a fixed setpoint table used my PPO2 at my max depth and translated it to EAD then using the PADI (eek) table made what I consider a resonable safe dive profile.

 

[Mr.X]

Ah but if you use it with a CCR unit is it still a dial-a-bend?
I.

I think DSAT needs to throw more money at dial-a-bends as research designed to extend the life of these plastic gizmos they made me buy during my IDAP crossover.

My dial-a-bends seems to be permanently fused to the plastic zippered slip cover which they charged an extra $10.00. :notify:

 

[wedivebc]

I think DSAT needs to throw more money at dial-a-bends as research designed to extend the life of these plastic gizmos they made me buy during my IDAP crossover.

My dial-a-bends seems to be permanently fused to the plastic zippered slip cover which they charged an extra $10.00. :notify:

I only ever use dial-a-bend when I am teaching PADI DM class and then I have to read the directions beforehand so I don't look like an idiot (which still doesn't always work).
I have used the flat RDP in a pinch

 

[BigJetDriver]

Dial-a-bend wheel....good one!! Bwa-ha-ha-ha-ha!!