Quote: (Originally Posted by
2stoned)
I believe that Micropore Cartridges are still favored in this design project.
Thanks for a good summary. We also hope that by exposing set of safety design practices, we can all learn from each other and establish the best practice across the industry. Nice dream.
On the Micropore cartridges there is an interesting technicality. We cannot use granules, by law. It must use cartridges. I will explain:
The law in Europe says rebreathers must meet EN14143:2003, and that requires meeting EN61508. The latter applies to any system incorporating any electronics or electrical system, or programmed system.
This means if the CCR has a controller, EN61508 applies to the whole lot.
CCRs using granules cannot meet EN61508. This means any CCR marked CE without a Micropore cartridge, is a lie.
The reason is users have too much variation in packing. A recent posting to select Inspiration users from Martin Parker highlights this problem. Not even all the instructors APD trained know how to pack it safely.
To meet EN61508 the whole system must meet SIL 4 requirements. There is no way on earth we can see how granules can meet that. Even using Micropore cartridges requires active monitoring of WOB etc to meet EN61508.
No CCR at the moment comes anywhere close to meeting EN61508. The best we have examined falls short by 4 orders of magnitude (more than 10,000:1) in terms of the critical failure level. The Open Revolution submissions should be the first to meet that requirement. It is a tall order, but the standard is there to prevent waste of your most precious resource, your life.
Cheers,
Alex