sense / nonsense of CO monitoring

[Wookie]

20+ years in neuroscience, including 10 working on retrograde transmitters, and I didn't know that

You want the google references, or am I just wrong? I have no frigging clue, but I can help you design your next Pressurized Water Reactor.

 

[UTscuba]

You want the google references, or am I just wrong? I have no frigging clue, but I can help you design your next Pressurized Water Reactor.

no you're correct, I looked it up, It's such a massive field that it's impossible to have more than a nodding acquaintence with everything outside your speciality

I'll keep that in mind, my current PWR is still under warranty though

 

[UTscuba]

We also exhale a tiny fraction of CO with each breath even when ambient is close to zero. It makes for a suitable bump gas for a CO monitor although a smokers breath is better.
The measurement of exhaled carbon monoxide in healthy smokers and non-smokers. - PubMed - NCBI

OK fair enough, I didn't know that either. What an educational day and it's only 10am

 

[DandyDon]

OK fair enough, I didn't know that either. What an educational day and it's only 10am

I guess that you don't bother to carry a CO tank tester and check every tank?

 

[UTscuba]

I guess that you don't bother to carry a CO tank tester and check every tank?

'bother' implies a lack of care.

But no I don't. I'm aware of the risks, and I appreciate your advocacy, but I personally put it under the heading of 'accepted risks inherent to diving'.

We all make our own choices as to what we're willing to throw the dice on, whether it's algorithm choice or solo diving,and that's one of my choices.

 

[DandyDon]

'bother' implies a lack of care.

But no I don't. I'm aware of the risks, and I appreciate your advocacy, but I personally put it under the heading of 'accepted risks inherent to diving'.

We all make our own choices as to what we're willing to throw the dice on, whether it's algorithm choice or solo diving,and that's one of my choices.

There have been no studies to my knowledge of how many injuries were caused by CO or how many drownings were. I suspect that the CO hits that lead to drownings largely go undiscovered. Back when Padi required samples to be tested by accredited labs quarterly, 97% were found to be safe and only 3% toxic but if I had known that 3 out of every hundred tanks I dived were dangerous, I would have taken actions sooner. But then, those tests were possibly done on samples taken only when the compressors were at their best, the requirements were never enforced, and they've long since been dropped - so it's a crapshoot.

 

[grf88]

I sometime wondered if it was a waste of money and time until I found 80 ppm in my son's tank.

 

[UTscuba]

There have been no studies to my knowledge of how many injuries were caused by CO or how many drownings were. I suspect that the CO hits that lead to drownings largely go undiscovered. Back when Padi required samples to be tested by accredited labs quarterly, 97% were found to be safe and only 3% toxic but if I had known that 3 out of every hundred tanks I dived were dangerous, I would have taken actions sooner. But then, those tests were possibly done on samples taken only when the compressors were at their best, the requirements were never enforced, and they've long since been dropped - so it's a crapshoot.

as I said, I do truly appreciate your advocacy

 

[UTscuba]

mulling more over this, thought I'd throw this out as an open question if there are any chemists out there. (@DandyDon ?)

Supposing both were drawn from the same source with a high CO concentration (eg a dysfunctional compressor), would nitrox ultimately have a lower CO concentration than a regular air mix?

My thinking is that:

CO is converted to CO2 in the presence of O2 according to

2CO + O2 <=> 2CO2

if you increase the concentration of O2, then Le Chatelier's Principle should move the CO/CO2/O2 equilibrium to the right in the direction of decreasing CO which should decrease the CO concentration present in your tank.

Or am I missing something?

 

[DandyDon]

Or am I missing something?

The whole idea is well beyond my paygrade. I'm no chemist or anything similar, and I hope that one will give you an answer - here, or someplace else. You suggested idea is oversimplified I think.

For

At room temperature, this reaction must be catalyzed. Details at https://www.enotes.com/homework-help/when-carbon-monoxide-combines-oxygen-what-produced-655293

CO is a potential fuel so it could be burned with oxygen to produce carbon dioxide, but not in a Nitrox situation.