Mailing List Archive Mailing List Archive
Denis,
I am glad to see that someone is evaluating the Fieno, here in France it is
difficult to obtain objective comments as no one is available. French rumor
says that the Fieno is hypoxic in real diving conditions. Could you tell us
more about the fieno's FiO2 variations?
For such a semi-closed unit, the equation is the following (thanks Mr Pyle):
(Qs x FsO2) - VO2
FiO2 = ---------------------
(Qs -VO2)
Where:
FiO2 = Inspired FO2
FsO2 = FO2 of the supply gas
Qs = flow rate of the supply gas
VO2 = rate of oxygen metabolism
In the Fieno, I read that the flowrate of supply gas is 5 Litre/min (from
Eric's Rebreather Page http://diver.ocean.washington.edu/rebreather.html).
So if you consider that the O2 metabolic rate varies from 0.5 Litre/min to 3
Litre/min according to the workload. We obtain the following range for the
FiO2 (considering a nitrox 40% as supply gas):
VO2=0.5 litre/min (rest) FiO2 = 33%
VO2=3 litre/min (intensive workload) FiO2 = -50%!!!
Yes minus 50% so that means no more O2 in the loop...
Could you give us a clue, is the injection rate of supply gas above 5
Litre/min?
Or should the Fieno be reserved to people limiting their O2 metabolic rate
to 1.2 Litre/min (FiO2=21%)? If so It may explain why the fieno is shown
with tiny japanese woman !
So as I presume that you are not a japanese woman with low O2 metabolic rate
:-),
where am I wrong?
If someone as info about O2 metabolic rate in diving conditions, I am
interested.
Many thanks again to share with us your experience.
Safe diving
Frederic
------------------------------------------------------------------------------
Frederic BADIER
Dowell Schlumberger
Schlumberger Riboud Product Centre
26 rue de la cavee (BP 202); 92142 Clamart Cedex, France
Tel : (33) 1 45 37 20 00 Switchboard
Tel : (33) 1 45 37 20 41 Direct Line
Fax : (33) 1 45 37 25 13
Sinet : badier@cl*.do*.sl*.co* (or DSA::BADIER)
------------------------------------------------------------------------------
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]