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Re: [PSUBS-MAILIST] Water depth sensing?



anything helps, thanks.
i had originally considered the low tech approach but as the project
progresses i keep moving the boundaries.  in one way i actually know it
could be done visually but where is the challenge?

steve

----- Original Message -----
From: "Al Secor" <wreckdiver@usadatanet.net>
To: <personal_submersibles@psubs.org>
Sent: Friday, February 20, 2004 12:42 PM
Subject: Re: [PSUBS-MAILIST] Water depth sensing?


> Steve,
>
> I'm using a pressure sensor from Digikey (www.digikey.com) for my
rebreather
> controller which uses a PIC processor. Mine is a 0-250 psi sensor which
will
> measure down to about 600 feet but you can get them that measure 0-100
psi.
> The particular sensor I'm using is a Measurement Specialties 2000519.  It
> has a .5-4.5v ratiometric output voltage and runs on 5 vdc and a 1/4" NPT
> pressure port.  The downside is they are somewhat pricey....about $100.00.
>
> Hope this helps....Al
>
> Al Secor  ARS: WA3PWX  Scuba Instructor SSI PDIC TDI
> http://www.geocities.com/SubDiverI
> ----- Original Message -----
> From: "steve" <steve@kobol.worldonline.co.uk>
> To: <personal_submersibles@psubs.org>
> Sent: Friday, February 20, 2004 3:37 AM
> Subject: Re: [PSUBS-MAILIST] Water depth sensing?
>
>
> > Hi All
> >
> > Unfortunately there is still no sign of the Kitteridge book but i expect
> the
> > US / UK post offices are taking their time.  maybe they read everything
> they
> > send???
> >
> > As part of my ROV project i want to look at a way of measuring the depth
> of
> > my vehicle.  I am toying with a Basic stamp 2 at the moment and wondered
> if
> > anyone had any ideas for a small (i.e. cheap) sensor that i could use
for
> > this purpose.
> > My design spec will only need to measure down to 20m in fresh or sea
> water.
> >
> > anybody got any useful ideas and know where i could source one?
> >
> > Best Regards
> >
> > Steve Bosworth
> > UK
> > ----- Original Message -----
> > From: "Dewey Mason" <drmason2001@yahoo.com>
> > To: <personal_submersibles@psubs.org>
> > Sent: Friday, February 20, 2004 1:50 AM
> > Subject: Re: [PSUBS-MAILIST] test of CO2 safety hardware - any
volunteers?
> >
> >
> > > If tested well, and found to work, this could serve as
> > > a backup unit to a commercial device, or even just as
> > > a novelty, but I agree in should be looked into. My 2
> > > cents.
> > >
> > > Dewey
> > > --- Pierre Poulin <pipo305@hotmail.com> wrote:
> > > > Erik,
> > > >
> > > > I will try it. I just need some time. I will try it
> > > > mainly for curiousity
> > > > and discution. I think that's all this group is all
> > > > about! To get new things
> > > > developed and discussed.
> > > >
> > > > Pierre Poulin
> > > >
> > > >
> > > >
> > > > >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.
> > > > >
> > > > >
> > > >
> > > >
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