Mailing List Archive

Mailing List: techdiver

Message Display

I've been comparing the USN CCMGUBA tables for 0.7 ATA constant partial
pressure O2 in N2 with my SRL accellerated air tables, and I was surprised
to find that the USN .7 tables allow longer no deco times than the air/02
tables.

This confuses me.  I'd think that the .7 tables would have longer no
deco times down to about 70fsw, then shorter times than air for deeper
depths.  I based this preconception on the breakeven point for 21% O2,
which is about 70 feet (3.3 ATM X .21% O2 = .69 ATA O2).

Strangely enough, the .7 tables allow a 9 minute NDL at 160', while the
SRL tables call for a 1 minute stop at 10 after a 5 minute exposure at 160
on air (1.2 ATA O2).  This seems to violate all the EAD theory I was taught
WRT O2 fraction and N2 loading.

Please shed some light if posible.

Thanks,
Scott.

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]