On Mon, Jan 19, 2015 at 1:02 PM, Anton Lundin <[email protected]> wrote: > > Hmm... As i read http://www.halcyon.net/RB80 it says > "8:1 ratio provides substantial gas extension" > > Is that old info or should i read that in some other way?
Counterlung ratio is 1:10, 8:1 is the real expected ratio in water due to mask clearing, ascent flush... http://www.frogkick.nl/files/michael_waldbrenner_rb80_rebreather.pdf (page 10). This is another article form the RB 2000 inventor Dr. Reinhard Buchaly: http://www.diritalia.it/images/pdf/quest/buchaly_rb80.pdf Unfortunately it's in Italian but you can easily translate with google: La ventilazione di questo rebreather semi chiuso a volume costante ha una ratio di 1:10 (page 2) La resa effettiva รจ di 1:8. Lo scarico del corrugato, profili yo-yo che frequentemente si trovano nelle grotte e l'espirazione dal naso non permettono di raggiungere la ratio ideale. (page 3) I was taught to use factory counterlung ratio. >> > another question: With a pSCR it could be possible to get into a low pO2 >> > situation, so in planning a dive we should warn in that case as we do for >> > high pO2. Which value is the minimal acceptable? Wikipedia mentions >> > 0.16bar. >> > >> >> Yes the O2 drop effect bring to have a MiOD (Minimum Operative Depth) >> for every gas. >> 0,16 is minimum PO2 to sustain life. Usually all tables reports MiOD >> for 0,16 and 0,21. >> > > 0.16 Is a good warning limit, but you should be really careful with such > low po2's. Don't try to walk stairs, or climb a ladder breathing that. > > You can do a bit of work breathing such a low po2, if you're > acclimatized to it, ex. skiing in the alps, but its quite tiresome. Of course 0,20 0,21 is the safe limit neverthless a lot of tables reports both limits. As 90% of info displayed by Subsurface they should be used with a grain of salt and from trained people. -- Davide https://vimeo.com/bocio/videos _______________________________________________ subsurface mailing list [email protected] http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface
