[PSUBS-MAILIST] CO2 ppm

[Alan James via Personal_Submersibles]

Hank,
have a look at Dr Phils life support paper on psubs, it quotes some limits.
There is a time factor variable. ie you can have a higher level for a short time.
If you come to conference brain damaged don't blame me though.
The k250s were designed with no life support. Just resurface
after an hour.
Alan


________________________________
 From: Sean T. Stevenson via Personal_Submersibles <personal_submersibles at psubs.org>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
Sent: Sunday, June 8, 2014 11:39 AM
Subject: Re: [PSUBS-MAILIST] CO2 ppm
 


Hank, 0.5% by volume is your maximum allowable, which is 5000 ppm, so technically that reading is okay; however if that is steady state, it doesn't provide a lot of margin for error.  How are you measuring the CO2?  I would check the calibration of the transducer, and also check that in an elevated CO2 environment (unmanned), turning the scrubber on will bring the level down to ~0 after some period of time.  The scrubber needs to keep up with the worst-case breathing / metabolism rate of the occupants.  Under ideal conditions (low stress, low exertion, fresh scrubber media), the scrubber should be capable of keeping the CO2 level at the low end of the allowable range.  A slow and steady climb in level is your indication that the media is becoming exhausted - you don't want to lose that early warning by operating close to maximum.

Sean


On 2014-06-07 17:26, hank pronk via Personal_Submersibles wrote:



I am heading to Slocan Lake tomorrow for work and a sub dive.  Today I did another life support test and the best I can do is 3700 ppm CO2, I think the absorbent is not so good or something.  Is 3700ppm good to go.
>Hank
>


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