JimC
Contributor
Should it not start at 100% then, which would be saturated to surface.. which is the state you would start at? Going below 100% would mean that after you surfaced you would ongass to 100%, or equalibrium at the surface.
Reverse Profile.
- Thread starter Liquid
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Should it not start at 100% then, which would be saturated to surface.. which is the state you would start at? Going below 100% would mean that after you surfaced you would ongass to 100%, or equalibrium at the surface.
Dr Deco
Contributor
- Messages
- 2,384
- Reaction score
- 96
- # of dives
- I just don't log dives
Dear Readers:
The compartments cannot saturate to a greater partial pressure than what is applied. The planner is probably indicating that the compartment is at 400% of what is physically possible at surface. I believe that some one said this already.
Most likely the WKPP people can do this is because
It is difficult to say with certainty what is occurring without a better picture of what is occurring. There is also the possibility that new physiology is present here. This was the case in no DCS appearing in null gravity with the astronauts on EVA.
Dr Deco :doctor:
The compartments cannot saturate to a greater partial pressure than what is applied. The planner is probably indicating that the compartment is at 400% of what is physically possible at surface. I believe that some one said this already.
Most likely the WKPP people can do this is because
- they are resistant to DCS
- the long compartments are not real if a separated gas phase does not form
- they decompress in the water and therefore eliminate most gas before reaching the surface (thus few micronuclei are present since they are not walking).
It is difficult to say with certainty what is occurring without a better picture of what is occurring. There is also the possibility that new physiology is present here. This was the case in no DCS appearing in null gravity with the astronauts on EVA.
Dr Deco :doctor:
The Iceni
Medical Moderator
I did as promised and it is not a simplistic as I surmised Jim.
I think Dr Deco has the answer. In any case, I am sure the allgorithm used does not continue to allow for on-gassing as a 900 minute dive to 50 metres resulted in an predicted maximum supersaturation of 630% in compartmant 8. I suppose it may be showing % of the predicted M value.
Getting a bit beyond me . . .
OP
If it's been said by Irvine, I belive it has some more to it, and you've cought is just a part of the whole thing.
BRW
Contributor
Just some info to pass about reverse profiles
(RPs).
At the Smithsonian Reverse Profiles Wkshp (2000)
we all agreed from data (and models) that RPs
were pretty much OK for depth increments of
30 fsw or less on successive dives, and for
depths not exceeding 130 fsw. This is obviously
recreational diving -- a SMALL subset of REAL
diving. The Wkshp recognized this, and we all
gave our blessings to ONLY that -- limited range
and statement of 130 fsw max, and deltas less
than 30 fsw for RPs What came out in news and
trade magazines did not reflect this -- as usual.
RPs for mixed gas, deco, and extended range
activities are a horse of a real different
color -- and are likely contraindicated in
general. Both on theory and experience.
Check some reported experience.
Here at LANL, repetitive RPs for deco diving
on trimix, heliox, and nitrox with increments
on RPs of 40 fsw and higher INCURRED an 8% to
16% DCI hit rate. This is reported in the
Proceedings Of The Smithsonian Wkshp On
Reverse Profiles, and in TDID. Here, we
NEVER dive RPs -- by data, model, and dive sense.
And we do cut corners in general -- but not on
RPs.
Al this is reflected in all released versions
of the RGBM -- tables, meters, software, etc.
But, if you do dive RPs, like everything else,
risk of DCS depends on age, diving fitness,
adaptation, temp, previous dives, deltas on RPs,
etc. And do recognize that George, JJ, Bill,
Scott, and most of WKPP are among the most
elite divers on this planet.
Bruce Wienke
Program Manager Computational Physics
Counterterror And Countermeasures Dive Team Ldr
(RPs).
At the Smithsonian Reverse Profiles Wkshp (2000)
we all agreed from data (and models) that RPs
were pretty much OK for depth increments of
30 fsw or less on successive dives, and for
depths not exceeding 130 fsw. This is obviously
recreational diving -- a SMALL subset of REAL
diving. The Wkshp recognized this, and we all
gave our blessings to ONLY that -- limited range
and statement of 130 fsw max, and deltas less
than 30 fsw for RPs What came out in news and
trade magazines did not reflect this -- as usual.
RPs for mixed gas, deco, and extended range
activities are a horse of a real different
color -- and are likely contraindicated in
general. Both on theory and experience.
Check some reported experience.
Here at LANL, repetitive RPs for deco diving
on trimix, heliox, and nitrox with increments
on RPs of 40 fsw and higher INCURRED an 8% to
16% DCI hit rate. This is reported in the
Proceedings Of The Smithsonian Wkshp On
Reverse Profiles, and in TDID. Here, we
NEVER dive RPs -- by data, model, and dive sense.
And we do cut corners in general -- but not on
RPs.
Al this is reflected in all released versions
of the RGBM -- tables, meters, software, etc.
But, if you do dive RPs, like everything else,
risk of DCS depends on age, diving fitness,
adaptation, temp, previous dives, deltas on RPs,
etc. And do recognize that George, JJ, Bill,
Scott, and most of WKPP are among the most
elite divers on this planet.
Bruce Wienke
Program Manager Computational Physics
Counterterror And Countermeasures Dive Team Ldr
BRW,
Thanks. I have read portions of the Smithsonian Reverse Profiles Wkshp. What I understood was exactly as you stated. The conclusion reached by many people and reported in some periodicals was that RP's are now ok because we have computers. People hear what they want. I have a copy of TDID and can't wait for some time to spend on it. And it will take some time.
Thanks. I have read portions of the Smithsonian Reverse Profiles Wkshp. What I understood was exactly as you stated. The conclusion reached by many people and reported in some periodicals was that RP's are now ok because we have computers. People hear what they want. I have a copy of TDID and can't wait for some time to spend on it. And it will take some time.
Similar threads
