Quote:
| Originally Posted by jknights If you have a Drager then you cn use and Alladin AIr Z O2 and an Oxy2 and this will provide you with pO2 readout and manage decompression.
Alternatively a VR3/2 with a P holder and an O2 cell will provide the same e.g. deco and pO2 readout.
Then there are the other home built units but theses dont provide both deco and pO2 management only pO2 readout. |
You could... but, you'd be as mad as a badger.
A single cell, in a RB enviroment should only be used as a crosscheck.
Two real obvious problems with deco tracking based on computers with PPO2 monitors;
1) Galvanic cells don't decay in a deterministic, predictable or constant way and are affected additionally and negitively by the enviroment inside the rebreather.
2) Computers remove all the additional safety fudge that used to occur with tables, PP02 tracking further removes more fudge. How close on any given day to the deco theories are our bodies?
For control logic either PPO2 or deco you need three cells, in a voting configuration (see reason 1), using the grey stuff between your ears to crosscheck that output and some of that uncommon sence, planning and some bailout strategies for
when it all goes wrong.
Never ever let the technology dive for you, plan your dive, dive your plan.
For an SCR (mine's a Submatix);
I plan my tank mix, based on all the usual dive parameters, additionally I calculate my rebreather "bag" mix. The bag mix is the nitrox mix I'm actually
rebreathing and this is based on nitrox mix from the tanks, flowrate and metabolism. I run a fixed nitrox mix deco plan based on my bag mix, a fixed depth based on the MOD PP02 in the bottles.
During the dive I have the EXT PPO2 on my VR3 turned off (thus it's not affecting my deco) and I can crosscheck with my PPO2 monitor on the VR3.
I dive to tables and use the computer as backup to my brain.
/F