From: Erik Muller <emuller@naic.edu>
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] test of CO2 safety hardware - any volunteers?
Date: Wed, 18 Feb 2004 12:23:52 -0400
Gail,
Many of the points you made are true. Let me address them one at a time:
>I'm wondering how accurate and useful a device like the one you describe
would be.
Indeed, as am I. This is why I am calling for people with air-tight hulls
to test the system. I am not suggesting that it be implemented on anyones
machine before testing its efficiency and it is developed.
>With reliable professionally-made devices being available, why would you
want to entrust something as important as life support to a $0.50
expedient?
That is true: you need to fold in the reliability of your equipment is to
the decisions you make in piloting and using your craft. However, to take
this question to the (unreasonable) extreme: why would you build your own
submarine when you can buy a perfectly operational one, brand-new for a few
hundred thousand or million? The fun is in the manufacture and learning how
it all works. However, care needs to be taken when using new systems in
that they are tested properly. Perhaps the 50c device works well enough as
a first order indicator. I dont know. I think it is worth finding out. I DO
know that it tests positive for a single breath, which has more that enough
oxygen remaining in it to be comfortable. If anything, I think this will be
an overly-conservative indicator. I can cite the age-old 'NASA vs USSR -
high tech gravity-proof-pen vs ordinary pencil' example as a great case
where cheaper is better. This might turn out to be one such case.
>From what I've learned, CO2 levels are taken care of by the scrubber, and
it's pretty easy to verify whether or not that's working. So this home
made CO2 sensing device doesn't sound necessary.
Sure, but some people dont have a scrubber in your machine. Others have
different systems to help reduce CO2 pp. Scrubbers are not part of
everyones hardware. I have not planned for one since my dives will be
short.
>Speaking for myself, I think I'd prefer the professional instrument.
Thats fine. Then this system is not for you. Some people dont have the
money, or want to try to make it all from the ground up (i.e. some people
like to grow their own for the fun of it). Im not insisting that this
system be immediatly implemented by all. Just that it is a system that
MIGHT be useful to SOME people, and is worth testing. Nothing more. If
tests show that it is unusable, then we have learned something. If tests
show that it IS useable, then we have also learned something. Its a win-win
world in this case.
There is a commercial in australia which says: 'you will never know if you
never go'. If its not tested, we will never know if it is useable, or not.
People have been objecting to my suggested technique for about a week, yet
no-one has tested it. I would really prefer that people object with numbers
or solid data, rather than opinions. The proof is in the pudding. We grow
by testing and learning. <insert other assorted feel-good anthropic cliches
here>.
Anyhow. thats enough from me.
EM.