Quote: (Originally Posted by
DanDunfee)
Duncan, these quotes were the source of my question as to 'what prompted you to go to a second (inh) counterlung ?'. I inferr from your answer that you didn't incorporate it into your current D5 mods. Correct ??. I don't mean to knitpick, just be sure I understood the D5 writeup and your answer. .
Dan - the original (001-004) units had 4l CL's on the exhale side - these contained the gas feed and P-ports for O2 monitoring (it was expedient). I experimented with a larger CL case to accomodate a 2 l exhale CL and 4 l inhale CL - it was too bulky. Woz's D5 has a 4 l inhale CL only with the gas feed upstream (inhale side) of the scrubber. D5#003 (retrofitted) and 006 (my current units) are based on this configuation. I wil do a write up in due course.
As far as I'm concerned, O2 injection is best upstream of the scrubber (for best gas mixing). Diluent (ideally - to be able to go open loop) and ppO2 monitoring (for reading what you are really breathing) should be on the inhale side. This is not news to anyone but I've re-learned this from experience.
In order to configure a slimline rig for squeezing through caves, one has to make compromises...e.g the CL is always at minimum loop. As shorter, fatter version is being considered, although I am tempted to abandon the whole idea for something better...