Mailing List Archive

Mailing List: techdiver

Message Display

To: chris@de*.de*.co*.uk*
Subject: Re: Final decompression gas choice?
From: Rodney Nairne <rnairne@sy*.DI*.oz*.au*>
Cc: techdiver@opal.com
Date: Tue, 18 Apr 1995 16:42:55 +1000 (EST)

Chris,
    The 1991 NOAA tests had some interesting results. Apparently,  a convulsion
occured on mixed gas after 40mins at a po2 of 1.6.  For pure oxygen, the lowest
po2 to produce a convultion was 1.76 ata.

One explanation is that mixed gas has a higher breathing resistance due to the
greater depths in which it is used. However, there is probably more to it than
that, and generally speaking high po2's are less likely to produce symptoms if
you are breathing pure 02.

For my air diving, I prefer 50/50ntx and 02 for deco, or if only one deco gas
needs to be carried, I use 02. I always carry more 02 than needed in case
symptoms develop, I can then just extend my deco.

BTW, one highly respected doctor stated that the probability of a convulsion
for divers at 9mtrs on 02 was 1 in 12000. Durations/prior exposures were not
mentioned.


Rod Nairne.

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]