----- Original Message -----
Sent: Sunday, August 28, 2005 2:54
PM
Subject: Re: Re: [PSUBS-MAILIST] O2
sensors
Yes as a home made close circuit rebreather diver i can say that a ppo2
meter is really simple to built.
basicly a simple 10 dollars lcd voltmeter and a pot are enough for the
electronics
but with no alarm
a system with an audible alarm can also be built cheaply .
what ojne have to know is that an o2 sensor is a very
fragile electrochemical device that can drift from a second to the other
with no warning
so any vital ppo2 system need to be doubled or trippled to be abble
for the operator to compare the readings
with 2 sensors one can know if the system works (if the reading are
close)
with 3 sensors one can know witch sensor is bad in case one starts to drift
.
a sensor life is usualy 12 to 24 monthes
as for the humidity problem don't care the r 22's have hydrophobic
membranes and works well in hyper humid condensing conditions like rebreathers
so i a bigger space like a sub cabin it will definitly be better.
I can help if necessarry.
regards
jean mi
----Message d'origine----
>Date: Sun, 28 Aug 2005
10:13:11 -0400
>De: Al Secor
>A:
personal_submersibles@psubs.org
>Sujet: Re: [PSUBS-MAILIST] O2 sensors
>
>Pierre,
>
>O2 sensors measure partial pressure
of O2, so if your sub cabin is at 2 atm, the
>sensor will read .42 in
air (assuming it's been calibrated to .21 at 1 atm).
>Be aware that
condensation on the face of the sensor can lead to erroneous
>readings
so you want to try to avoid condensation directly on the face even
>though some are manufactured with hydrophobic membranes.
>
>A good place to get sensors is from Patrick at oxycheq.com. His prices
are very
>reasonable and he provides good service. (I have no relation
to Patrick, just
>a satisfied customer). I use Teledyne R-22D sensors
in my homebuilt
>rebreather. A very simple O2 meter can be built from a
recalibrated DVM
> module. There are several sources on the web that
describe how to do it and I
>think Patrick's webpage also describes it.
>
>Hope this helps.
>
>Al
>
>Al
Secor ARS: WA3PWX Scuba Instructor SSI PDIC TDI
>http://www.geocities.com/SubDiverI
>
>
>
>Quoting Marie-Andrée et Pierre :
>
>> Hi guys,
>>
>> After seing Jon's presentation
at the convention I decided to go with a
>> scrubber and a O2
injection device.
>>
>> My question is: Will an oxygen
sensor work for a dry-ambient sub? How does
>> the sensor work? I
know it give a different voltage outpout depending on the
>>
>> amount of oxygen in the air. but what happened when put under
pressure? Will
>>
>> it track PPM of oxygen in the air or
the % of oxygen in the air? Will it
>> detect 21% at 1atm, 42% at
2atm, 176% at 5atm, etc...
>>
>> Does anybody here have
experience with a scrubber/O2 system in an ambient
>> sub?
>>
>> The reason I decided to go scrubber/O2 is that I
have about 35-40 minutes
>> inside my sub before I feel the effect
of too much CO2 in the cabine. If I
>> refresh the air inside the
cabine by injecting fresh air from my tanks, it
>> is not very
effective and takes alot of air.
>>
>> Thank you all!
>>
>> Pierre "O2" Poulin
>>
>>
>>
>>
>>
>>
************************************************************************
>>
************************************************************************
>>
************************************************************************
>> The personal submersibles mailing list complies with the US
Federal
>> CAN-SPAM Act of 2003. Your email address appears in our
database
>> because either you, or someone you know, requested you
receive messages
>> from our organization.
>>
>>
If you want to be removed from this mailing list simply click on the
>> link below or send a blank email message to:
>>
removeme-personal_submersibles@psubs.org
>>
>> Removal of
your email address from this mailing list occurs by an
>> automated
process and should be complete within five minutes of
>> our server
receiving your request.
>>
>> PSUBS.ORG
>> PO
Box 311
>> Weare, NH 03281
>> 603-529-1100
>>
************************************************************************
>>
************************************************************************
>>
************************************************************************
>>
>>
>
>
>
>
>
>
************************************************************************
>************************************************************************
>************************************************************************
>The personal submersibles mailing list complies with the US Federal
>CAN-SPAM Act of 2003. Your email address appears in our database
>because either you, or someone you know, requested you receive
messages
>from our organization.
>
> If you want to be
removed from this mailing list simply click on the
>link below or send
a blank email message to:
> removeme-personal_submersibles@psubs.org
>
>Removal of your email address from this mailing list occurs
by an
>automated process and should be complete within five minutes of
>our server receiving your request.
>
>PSUBS.ORG
>PO Box 311
>Weare, NH 03281
>603-529-1100
>
************************************************************************
>************************************************************************
>************************************************************************
>
>
************************************************************************
************************************************************************
************************************************************************ The
personal submersibles mailing list complies with the US Federal CAN-SPAM Act
of 2003. Your email address appears in our database because either you, or
someone you know, requested you receive messages from our organization. If you
want to be removed from this mailing list simply click on the link below or
send a blank email message to: removeme-personal_submersibles@psubs.org
Removal of your email address from this mailing list occurs by an automated
process and should be complete within five minutes of our server receiving
your request. PSUBS.ORG PO Box 311 Weare, NH 03281 603-529-1100
************************************************************************
************************************************************************
************************************************************************