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Den 21:31 21-01-00 skrev David Reinhard: >I have just been catching up with some of the interesting material in the >"Sample Deco Dive - 220 for 25" thread (I've been busy so haven't read it >all yet). I haven't yet seen the Decoplanner software but what i am >wondering is how the gradient factors in that program relate to those in >'GAP'. JJ refers to figures such as 10-30, 40-60 etc. In GAP the gradient >factors are in terms of decimals (between 0 and 1.0). Is there a simple >relationship between these figures (such as a factor of 100) eg 0.2 on GAP >is equivalent to 20 on decoplanner? So when JJ recommends starting with 30 >low and 80 high can this be translated to 0.3 low and 0.8 high on GAP? Yup, correct. DecoPlan's 20% is equal to GAP's 0,2. Included with GAP (in the help file and as a PDF document) you'll find Erik Baker's article on GF. He recommends a surface M-value (_not_ GF Hi) of 85% and a GF Hi of 0,5-0,5 but I find the latter very conservative. The articles are also included with DecoPlan. You may also find tham at the link below under 'reference'. > Forgive me if this is a stupid question, or I have got it > entirely wrong, >but the gradient factors concept is new to me. You should read the Baker articles included with GAP (and DecoPlanner): they are very good. I have read them 10 times so I'm starting to get the gist of them :-) >Another question, while I am at it. Setting the low gradient factor to a >smaller number (eg 0.1 on GAP) gives deeper stops, but I presume that even >the deepest of stops given on these programs is still in the theoretical >"deco zone"? Yup. A GF Lo of 0% or 0,0 generates the first stop right there where we move into the decompression zone. > Judging by the quick example I worked out last night for a 50m >dive 0.1 gave the deepest stop at around the same point as the 'Pyle' >method. Would this be generally true, or are some people thinking that >'Pyle' stops may be a little too deep? Again, it's in the "Clearing up the confusion about deep stops" article by Erik Baker. Pyle stop may actually be deeper than the decompression zone! >Also why choose (ie what >advantages/disadvantages in choosing) the deep stops to start shallower if >you can do deeper stops that are still in the "deco zone"? The deeper you start, the more deco but also better deco (in very rough terms). On a dive to 30 metres for 25 min on EAN I would not set GF Lo at 0,1. -- Regards, Peter Fjelsten --------------------------------------------- Sidekick for the author of GAP (Gas Absorption Program) - a FREE Win32 decompression software with Baker's Gradient Factor model and a GUI can be found at http://www.tekdyk.dk/GAP -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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