Re: P.S.

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Posted by MHK on November 20, 2000 at 10:42:38:

In Reply to: Re: P.S. posted by AADIVER on November 17, 2000 at 19:27:26:


The Nitrox computer's will NOT be of much use while adding He to the mix..

Most computer's use the Buhlman modified subset c algorithm for computing NDL's. The problem with the Buhlman models is that they do NOT consider He so your tissue groups will be all over the place.. The deeper you go you start loading the faster tissue groups, which uptake and offgas at different ratio's than an EANx mix..

Computer algorithms calculate in real time as opposed to the Buhlman modifed subset B, which calculates in planned time.. That's basically the difference between a table and a computer.. Which is why you can get extended BT's with a computer.. The computer constatntly computes the profile and accounts for changing depths and times.. To the extent each tissue group is being updated by programming a different gas you could be asking for trouble..

If all else fails and you had to use the Nitrox computer I would remind you that He, uptakes and offgases 2.65 time faster than N2, so while some could recalculate the differential it would be more trouble and probably less reliable than if you simply cut tables on the surface and stayed with that plan...

If you have some specific run times and gases to compare send them and I'll run them to give you a basis for comparison..


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