Re: [PSUBS-MAILIST] co2 monitor source

["Cliff Redus" <dr_redus@devtex.net>]

Alan

> I like the Nuytten method, too. I'm planning to revamp
> my O2/CO2 system this year. Any thoughts on a good,
> compact scrubber for my tiny, single-place Explorer?

I have seen some face mask type units that have the cartridge in the mask
but I don't know of any non face mask complete units.  What I have chosen to
do is use a transparent cartridge holder from Aqua-Pure (AP12T) and make my
own cartridges.  The clear lexan bowl lets you monitor the color change in
the absorbent.  And the size allows me to have my normal mission duration (7
hours) in one cartridge.  I then store the remaining cartridges to give me
72 hours of emergency time. I am using a  marine compact PVC inline blower
from Jabsco (12 VDC, 3" In-line, model 3048900000) to circulate air through
cartridge holder and cartridge. My intake point is the lowest part of my
boat at the stern and my exhaust point is directed blow across my bow
viewport (Busby indicated that this might help keep the viewport clear).  I
have some concerns that the blower may be to noisy and not efficient at the
reduced flowrate caused by the head loss across the absorbent.  If it is to
loud, I will look or another.  Maybe we can get Alec to tell us what he is
using to circulate air in his boat?  I know he is also building his own
system.

>Also,would you use a mechanical or electronicpressure
> sensor?

I am using 600-1100mbar barometric pressure sensor from Omega (
PX2760-600A5V  ). This sensor has an accuracy of  +/- 0.25% span  with 0.1
to 5.1 VDC signal output (3-wire). Because I am using a PLC, I can bring the
cabin pressure signal in as an analog input and send out from the PLC a
digital output that activates the O2 solenoid valve.

If you find an off the shelf scrubber system for small cabins, please post.

On a previous thread, did you every find and test a solution for your
problem of air bubbles sticking to your bow viewport?

Cliff