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DanDunfee · 16th July 2007, 20:45

I think that you'll find that knowing a good, representative TV for yourself is a much more useful number than FVC for most of the calculations you'll make.

I, for one, believe that too many RBs have too large total CL volumes. This occurs for various reasons, including some modern, commercial, manufacturers designing it that way to minimize WOB, to squeak by the CE certification requirements or for marketing purposes. .

I believe that excessive CL volumes have certain penalties, including:
* Carrying excessive weight to offset the excessive buoyancy
* Greater absolute CL volume changes with depth changes, and more gas used
or dumped adjusting for the volume and buoyancy changes. .
* More trim problems in some cases.

Most, more modern, combat UBA systems use total CL free volumes in the 5-8 l range whether they use Back-mounted, OTS, or Chest-Pack CLs. . I've recently designed a single, chest-pack CL for a personal rig, which is a heavily modded RG-UF/M, and is intended to have a CL free volume of ~ 6 l.

16th July 2007, 20:45	#16 (permalink)
DanDunfee Custom Title Allowed! Current Rebreather/s: Other CCR Other SCR Home Build Other Rebreather/s: Not Bought Yet Other CCR Other SCR Home Build Join Date: Sep 2005 Location: Virginia, USA Posts: 204	Re: Excessive counterlung volume on my MEG I think that you'll find that knowing a good, representative TV for yourself is a much more useful number than FVC for most of the calculations you'll make. I, for one, believe that too many RBs have too large total CL volumes. This occurs for various reasons, including some modern, commercial, manufacturers designing it that way to minimize WOB, to squeak by the CE certification requirements or for marketing purposes. . I believe that excessive CL volumes have certain penalties, including: * Carrying excessive weight to offset the excessive buoyancy * Greater absolute CL volume changes with depth changes, and more gas used or dumped adjusting for the volume and buoyancy changes. . * More trim problems in some cases. Most, more modern, combat UBA systems use total CL free volumes in the 5-8 l range whether they use Back-mounted, OTS, or Chest-Pack CLs. . I've recently designed a single, chest-pack CL for a personal rig, which is a heavily modded RG-UF/M, and is intended to have a CL free volume of ~ 6 l. __________________ There are 'Bold' divers and old divers, but NO old, ' Bold ' divers Last edited by DanDunfee : 16th July 2007 at 21:07.
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