Chris - this is exactly true - the sensors do not like being in humid gas (as 
in a rebreather), and Draeger recognizes this. Stone is still trying to come 
up 
with various Rube Goldberg schemes to deal with this, but the problem he is 
compounding in the process is the task loading, which is what kills rebreather 
divers on closed circuit (even if the machine deos not get them) . Stone has 
added audible warnings for this, but then you have to assume all of this works, 
and all of it is getting its information from sensors that do not do well in 
humidity, so we have nothing useful for cave diving other than our rig, and it 
is quite obvious that we have proven that .

   What really amazes me is that the other manufacturers, who are really just 
shade tree operators , keep pretending these things work. I am not including 
Stone in that category, has the mere fact that he as tried to offer a sytem to 
deal with the problem indiceates that he is firumly aware of it, while the 
others are rolling the dice. Just remember, Gavin wontl; dive one, and he is
the 
EX19 and MK 16 guy , and all of us will dive mine, so what does that tell you.

On Mon, 13 Jan 1997, Chris Hellas <chris@de*.de*.co*.uk*> wrote:
>In message <199701121822.KAA22567@m2*.in*.co*>, George Irvine
><gmiiii@in*.co*> writes
>
>Snip.....
>
>>
>>   We had the only new rebreather technology, Stone had the only new attempt 
at 
>>solving the sensor problem (blowing dry gas over them - he used to heat them, 
>>and before that he had Rosary Beads attached to them.
>
>G
>
>   Interesting that you point this out - I'm sure most people do not
>know the problems.
>
>As regards the use of active oxygen control systems on closed circuit
>rebreathers it's maybe worth remembering a conversation I had with
>Drager in mid 1996. 
>
>You may or may not know that they dabbled in electronic C2 a couple of
>years ago (SMS2000E) and decided not to persue the concept. They have a
>100 metre semi closed self mixing gas unit (military) - the M100M. It
>seemed a logical question as to why they never persued the electronic
>avenue. The answer was short but interesting.......
>
>        "until such time that we can develop a suitably moisture
>tolerant oxygen monitoring system we do not envisage entering the market
>with rebreathers that have electronic control systems"
>
>Food for thought........
>
>Regards
>
> 
>Chris Hellas         e-mail - chris@de*.de*.co*.uk*
>
>


George M. Irvine III
DIR WKPP
Woodville Karst Plain Project
1400 SE 11 ST Ft Lauderdale, FL 33316
954-493-6655 FAX 6698
Email gmiiii@in*.co*

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