oh, sorry...I thought that had been covered.

Air breaks on the lowest fo2 you have, should be back gas, every 25 minutes
max for 5 minutes min.

I thought you were arguing 100%...my bad.

Trout


----------
> From: M.S.Langborg <findir@an*.co*.uk*>
> To: Jesse Armantrout <armantrout@wo*.at*.ne*>; Joel Silverstein
<joelsilverstein@wo*.at*.ne*>
> Cc: techdiver@aquanaut.com
> Subject: Re: 80% arrrgh!! was Re: On the left
> Date: Tuesday, November 24, 1998 3:56 PM
> 
> Yes, am I wrong ???
> 
> But I still haven't got an answer to my question
> 
> Mike
> 
> -----Original Message-----
> From: Jesse Armantrout <armantrout@wo*.at*.ne*>
> To: M.S.Langborg <findir@an*.co*.uk*>; Joel Silverstein
> <joelsilverstein@wo*.at*.ne*>
> Cc: techdiver@aquanaut.com <techdiver@aquanaut.com>
> Date: 24 November 1998 21:48
> Subject: Re: 80% arrrgh!! was Re: On the left
> 
> 
> >Then do you think it is that all of the "major" divers use 100% ?
> >
> >----------
> >> From: M.S.Langborg <findir@an*.co*.uk*>
> >> To: Joel Silverstein <joelsilverstein@wo*.at*.ne*>
> >> Cc: techdiver@aquanaut.com
> >> Subject: Re: 80% arrrgh!! was Re: On the left
> >> Date: Tuesday, November 24, 1998 12:28 PM
> >>
> >> No, as you know, all the "major" agencies teach deco using 80 %.
> >>
> >> Mike
> >>
> >>
> >>
> >> -----Original Message-----
> >> From: Joel Silverstein <joelsilverstein@wo*.at*.ne*>
> >> To: Mike Langborg <mslangborg@cl*.ne*>
> >> Cc: techdiver@aquanaut.com <techdiver@aquanaut.com>
> >> Date: 24 November 1998 02:08
> >> Subject: Re: 80% arrrgh!! was Re: On the left
> >>
> >>
> >> >yup   -- wasnt that covered in you training program?
> >> >
> >> >
> >> >
> >> >
> >> >At 09:42 PM 11/23/1998 -0000, you wrote:
> >> >>Ok, so 100% oxygen is the way to go. What do you do about
"airbrakes".
> >> >>
> >> >>When, i.e. after 20/25min?
> >> >>for how long, i.e. 5/10 min?
> >> >>And what gas do you use for "airbrakes" i.e your 50%, your 36% or
your
> >> >>bottommix?
> >> >>
> >> >>Mike
> >> >>
> >> >>
> >> >>
> >> >>-----Original Message-----
> >> >>From: Joel Silverstein <joelsilverstein@wo*.at*.ne*>
> >> >>To: gwaw@ix*.ne*.co* <gwaw@ix*.ne*.co*>
> >> >>Cc: Techdiver@aquanaut.com <Techdiver@aquanaut.com>
> >> >>Date: 23 November 1998 16:23
> >> >>Subject: 80% arrrgh!! was Re: On the left
> >> >>
> >> >>
> >> >>>Dear Arnie,
> >> >>>
> >> >>>It is quite easy to pump 100% oxygen to 3000 psi -- the dive shop
> >needs
> >> to
> >> >>>make the investment in a proper oxygen service rated Haskel Gas
> >booster.
> >> >>>Most any reputable dive center who is mixing gas for the consumer
> >should
> >> >>>have one, anyone that does not should step up pet the pony and buy
> >one.
> >> >>>
> >> >>>80% EAN was not created from a decompression standpoint it was
> >justified
> >> by
> >> >>>those who did not have a gas booster. Here's why. Oxygen gets
> >delivered
> >> in
> >> >>>2400 psi bottles, (some major cities have gas suppliers who can
supply
> >at
> >> >>>3500 psi) however you can cascade into a 3000 psi rated cylinder
about
> >> 2250
> >> >>>psi of oxygen top up to 3k with air and you have 80% oxygen
content.
> >> Simple
> >> >>>enough.  However .......
> >> >>>
> >> >>>80% EAN limits you severely. 1. at 20 and 10 fsw its PPO2  is too
low
> >> make
> >> >>>it useful, at 40 fsw its too high for maximum exposure limits.
> >> >>>
> >> >>>10 fsw 1.04 po2  too low
> >> >>>20 fsw 1.28 po2  too low
> >> >>>30 fsw 1.53 po2  borderline
> >> >>>40 fsw 1.77 po2  too high
> >> >>>
> >> >>>Where as 100% oxygen is
> >> >>>
> >> >>>10 fsw 1.30 po2
> >> >>>20 fsw 1.61 po2
> >> >>>
> >> >>>(with the 10 fsw stop normally being taken at 20 fsw
> >> >>>
> >> >>>Advocates of the EAN80 (a/k/a stroke mix) have come up with a
variety
> >of
> >> >>>reasons to justify not using 100% oxygen --- one of the great ones
is
> >> "its
> >> >>>good for divers who have trouble holding buoyancy at 10 and 20 fsw"
> >> >>>frankly if a technical diver cant hold a 20 fsw stop --- they
should
> >go
> >> >>>bowling and get the hell out of the water.
> >> >>>
> >> >>>Most divers who are using accelerated decompression tables have
> >> >>>standardized on their decompression mixes.  (some are finding that
> >> >>>hyperoxginated heliox mixes are working well too though that is
beyond
> >> the
> >> >>>scope of this email)
> >> >>>
> >> >>>EAN 36 from 110 fsw
> >> >>>EAN 50 from 70 fsw
> >> >>>100% oxygen from 20 fsw
> >> >>>
> >> >>>Granted when you run one of the consumer dive profiling softwares
you
> >may
> >> >>>see only a small decrease in decompression time -- maybe 5 minutes
by
> >> using
> >> >>>100% over EAN80. and though you may belive that is not a
significant
> >> enough
> >> >>>advantage to make sure you have 100% oxygen here are a few more
> >> >>>non-scientific reasons.  From a mixing standpoint unless you are
using
> >> >>>exceptionally clean hyper filtrated air or air produced from an oil
> >free
> >> >>>compressor there is risk of explosion when mixing high pressure air
on
> >> top
> >> >>>of 100% oxygen. It probably has not happened yet --- but some day
some
> >> >>>goober will blow up a building doing it. Even if you are using a 30
> >cuber
> >> >>>(small) just cascading 2400 psi oxygen in it will give you 24 cuft
of
> >> >>>oxygen -- for deco thats easily 40 minutes worth, which is a lot of
> >gas.
> >> No
> >> >>>need to goober around making EAN80 for the other 6 cuft, its just
too
> >> much
> >> >>>work for it and I am sure it costs a bit more, besides if you are
> >doing a
> >> >>>dive that requires much more than 40 minutes of oxygen
decompression
> >you
> >> >>>would want a bigger tank. The fact that a tank has a pressure
rating
> >of
> >> >>>3000 does not mean you have to fill it to that level. I have an
> >excellent
> >> >>>tank chart for all currently available tanks in the US on our web
site
> >-
> >> go
> >> >>>look at it. Next; most consumer available oxygen analyzers using
> >> >>>electrochemical sensors can be off by as much as 2% in their
readings,
> >so
> >> >>>is your 80% really 80 or is it 78? Whereas pure oxygen is upwards
of
> >99%
> >> >>>pure -- it's a known item.
> >> >>>
> >> >>>Arnie, as a techie in training you have an opportunity right in
front
> >of
> >> >>>you. It's two roads ... the left road is filled with exploration,
> >> >>>friendships, technology and long proven safety procedures. The
right
> >road
> >> >>>is bumpy, full of mis answered questions, body bags, and strokified
> >> >>>convolution. I get the feeling your want to take the high road and
do
> >it
> >> >>>right. In Judaic studies we are taught to ask why not to follow
> >blindly.
> >> >>>So in this very long winding response (If I had more time it would
> >have
> >> >>>been shorter) the answer is .... EAN80 buys you 6 cuft more gas,
but
> >buys
> >> >>>you nothing else. Take no shortcuts when it comes to technical
diving.
> >> >>>
> >> >>>Good Luck
> >> >>>
> >> >>>
> >> >>>
> >> >>>
> >> >>>
> >> >>>
> >> >>>
> >> >>>At 10:21 PM 11/22/1998 -0800, you wrote:
> >> >>>>Joel,
> >> >>>>
> >> >>>>Another question for you.  It is prompted by your post on the
bottle
> >> >>>>marking issue.
> >> >>>>
> >> >>>>What is the advantage of 100% O2 compared to 80% O2.  I've been
using
> >> >>>>the latter for deco.  For one, it is somewhat easier to get at
local
> >> >>>>dive shops because it is harder to pump the 100% to 3,000 psi, but
> >that
> >> >>>>is merely convenience.  More importantly, I can get on the 80% at
> >30ft
> >> >>>>and have the advantage of breathing a higher gradient gas mix
sooner
> >> >>>>than waiting to the 20ft stop.  The published tables I've seen
give
> >no
> >> >>>>time advantage to doing deco on 100% over 80%.
> >> >>>>
> >> >>>>What is your view and why?  TIA.
> >> >>>>
> >> >>>>Blow gentle bubbles,
> >> >>>>
> >> >>>>Arnie
> >> >>>>Tech Diver in Training
> >> >>>>
> >> >>>Joel Silverstein
> >> >>>Scuba Training + Travel Co.
> >> >>>http://www.NitroxDiver.com
> >> >>>--
> >> >>>Send mail for the `techdiver' mailing list to
> >`techdiver@aquanaut.com'.
> >> >>>Send subscribe/unsubscribe requests to
> >`techdiver-request@aquanaut.com'.
> >> >>>
> >> >>>
> >> >>
> >> >>
> >> >>
> >> >Joel Silverstein
> >> >Scuba Training + Travel Co.
> >> >http://www.NitroxDiver.com
> >> >
> >> >
> >>
> >> --
> >> Send mail for the `techdiver' mailing list to
`techdiver@aquanaut.com'.
> >> Send subscribe/unsubscribe requests to
`techdiver-request@aquanaut.com'.
> >
> >
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