Quote: (Originally Posted by 2stoned)
Alex…
As I understand this:
This reading is done in the plenum after the CO2 absorption.
With the Auto ShuDBoF now separated, does that mean that the ShutOf valve is positioned prior to the “sniffing electronics” so that the Diluent gas used in BailOut-SC or -OC mode is "sniffed" and included in the calculations for stops and deco?
You have identified an area very worthy of debate.
The sensing is the gas going into the breathing hose, prior to the shut off valve.
What happens on deco if the user has bailed out, is that it assumes the gas is what is in that space. If the user is on O.C., then there can be quite an error. This is the reason we moved the exhale valve from the mouthpiece to the exhale bag: it means gas flows past the exhale mushroom and does get into the loop.
Quote: (Originally Posted by 2stoned)
Thus that the Computer always knows what you breathe as long as you stay on the loop (SC and OC feed through the Rebreather inhale hose and OverPressureValve is in exhale lung).
Correct, and an error if the user is not on the loop (ie an error in the calculation).
Quote: (Originally Posted by 2stoned)
Is there an option to tell the computer that you switched to a new gas, as on separate OC, so that these gasses can be calculated for deco requirements? (Gas choice ON/BAIL/OFF) (Can you program-in gasses?)
There is no means to do that right now, but it may be necessary.
Quote: (Originally Posted by 2stoned)
I hope that this deco-comp will not Lock-Out the diver, when he finds himself in an emergency, like helping someone to surface, and then go down to deco.
-A safe Rebreather should never let you down. Please none of this “USE TABLES”
I agree, tables is not really the solution though divers should always have them.
At the same time, we do not want divers telling the unit what gas they think they are using. Too often it is in error, especially with certain boat operators who do not seem to have the faintest idea of blending when they provide gas: we give the mix free if it is out by more than 2%, but I have bought gas at silly cost on some boats where even the O2 is out by 50% from that ordered and what the He is is anyone´s guess as there was no analyser on board and no scales to make a guess with.
At the moment, if the shut off valve closes, it will continue with the same dil gas as the diver has been using. This is not a satisfactory solution.
We are going to have to find a better solution for the deco calc in this bail out condition. We are hoping the moving the exhale valve gets enough gas into the sample area to do something. We are also trying a shut off valve which does not close entirely, but only 95%, so some gas gets around the loop: it is enough in the case of a flood to stop water in the hoses. An area needing development ...
Quote: (Originally Posted by 2stoned)
Alex, we are very ready for a new thread on the rev4.
These threads are getting hard to read (the info is spread out wide and I have a short memory).
I have the same problem. The Open Revolution area should be up soon. Very soon, with all these things separated into different threads.
Thanks again for the time to think these things out so carefully.
Cheers
Alex