Posted by green trees on October 03, 2003 at 18:23:43:
In Reply to: DCIEM vs RGBM posted by Seaurchin on October 03, 2003 at 07:02:01:
At a very high level, not to be used for real diving, I'll give the following:
I assume you are familiar with the Haldanian model as extended by buhlmann. This basically sets a critical saturation for several different compartments. Diving is done so that the compartment saturation is below the critical level. These compartments saturate and desaturate in parallel.
The DCIEM model is different in that the compartments are in series rather than parallel.
The RGBM model has several addtions, but get's it's name from "Reduced Gradient", which is limiting not only the absolute critical pressures but the relative critical pressures. This is to help with the second part of it's name "Bubble Model", in which RBGM models off-gasing as a two-phase --the N2 comes out of solution and bubbles (becomes a gas phase) in the body, rather than the simpler model that simply looks at the disolved N2 (which being disolved is in liquid phase).
Lots of info on deco theory on the web, but I wouldn't trust my life to it....
GT