Dry cave bad air

[phillip1]

So we have been finding more and more springs that sometimes come up in large dry caves, then go back down etc..
some of these dry caves have waterfalls where I assume the air would be ok, sometimes we need to take off gear to climb over to other side to keep diving.

What we do to test air is one diver takes out reg and takes a few breaths, then a few more etc.. while other diver has reg in and ready to shove reg back into testers mouth should they pass out. Is this dumb or the way to go.

Are there any dry caves/gas pockets that have air so bad you could die/pass out in a few breaths? what procedures do you sump divers do to test for air in these situations?



Thanks

[Great White7]

What we do to test air is one diver takes out reg and takes a few breaths, then a few more etc.. while other diver has reg in and ready to shove reg back into testers mouth should they pass out.

lol.

Ok I guess its prob the only way to do it other than have some sort of analyzer but I would not be volunteering to be the one who takes the breaths.

If the person does go UC, how far are you from EMS?

[Great White7]

what procedures do you sump divers do to test for air in these situations?

They take canaries in dry bags. lol.
No idea but it was something I was thinking about the other day.

[wingman]

So we have been finding more and more springs that sometimes come up in large dry caves, then go back down etc..
some of these dry caves have waterfalls where I assume the air would be ok, sometimes we need to take off gear to climb over to other side to keep diving.

What we do to test air is one diver takes out reg and takes a few breaths, then a few more etc.. while other diver has reg in and ready to shove reg back into testers mouth should they pass out. Is this dumb or the way to go.

Are there any dry caves/gas pockets that have air so bad you could die/pass out in a few breaths? what procedures do you sump divers do to test for air in these situations?
Thanks

One alternative would be to take a lighter in a dry bag and then simply see if it ignites and compare the flame to its open air magnitude.

[FW]

One alternative would be to take a lighter in a dry bag and then simply see if it ignites and compare the flame to its open air magnitude.

I like that idea! I typically do what Phillip1 suggested, but there isn't always someone else around.

[wingman]

I like that idea! I typically do what Phillip1 suggested, but there isn't always someone else around.

Must give credit to Jason Gulley...we went into a dry cave in the Ocala area and it was a bit lacking in O2 and he used this method to evaluate the breathability ...the flame would barely go and needless to say I was a bit short of breath on exit....

[Webmaster]

Other than breathing it or hauling some actual instrumentation into the cave to test the air, the flame test is certainly the most practical method of detection.

Bad air is not fun. You can still develop symptoms when a lighter will light. Headache, increased breathing rate, shortness of breath, dizziness, nausea. Some develop more strongly in some than others, and it can creep up on you.

I've had a couple of close calls. It can take a while to notice. If you're not exerting, like sitting waiting on others it can take longer to develop symptoms.

I know this is not always true of all places, but we've only run into a relatively few spots here where it was bad enough that we immediately had to get out NOW. These were mostly where a lot of vegetative matter had washed into a blind pit where the CO2 collected. That's one of the other clues to look for, if there's a lot of dead vegetation there be especially cautious. I've never been anywhere (knock on wood) that was bad enough that just a few breaths would render you unconscious.

When we were originally looking at this years ago, because we were finding a lot of bad caves locally, the instruments to detect CO2 were clunky, expendable, expensive and better suited to a lab environment. I believe at least one rebreather manufacturer is selling a CO2 monitor that works at 1 ATM now. If you didn't mind the expense, this might be able to be repurposed for sumps and questionable cave atmospheres.

[Aotus]

I know nothing about this, but the previous posts suggest the principal concerns are 1) insufficient O2, and 2) high levels of CO2. Are there other concerns?

1) An O2 analyzer could be brought in a dry bag, right?
2) Mobile CO2 meters seem a little tricky to find (most need an outlet) but here are a couple:
- http://www.extech.com/instruments/pr...d=7&prodid=527
- http://www.amazon.com/Amprobe-CO2-10.../dp/B0046HEFEU

[Rhino]

I know nothing about this, but the previous posts suggest the principal concerns are 1) insufficient O2, and 2) high levels of CO2. Are there other concerns?

1) An O2 analyzer could be brought in a dry bag, right?

If you're referring to a diving O2 analyzer, I don't think that would reflect the quantity of O2 in a given space. And, even if it somehow could, would the presence of CO2 be read by an O2 analyzer as just increasing O2 content? Perhaps keeping track of the readings on an O2 monitor could be helpful to show the depletion of O2 over time.

[FW]

I know nothing about this, but the previous posts suggest the principal concerns are 1) insufficient O2, and 2) high levels of CO2. Are there other concerns?

1) An O2 analyzer could be brought in a dry bag, right?
2) Mobile CO2 meters seem a little tricky to find (most need an outlet) but here are a couple:
- http://www.extech.com/instruments/pr...d=7&prodid=527
- http://www.amazon.com/Amprobe-CO2-10.../dp/B0046HEFEU

If you're referring to a diving O2 analyzer, I don't think that would reflect the quantity of O2 in a given space. And, even if it somehow could, would the presence of CO2 be read by an O2 analyzer as just increasing O2 content? Perhaps keeping track of the readings on an O2 monitor could be helpful to show the depletion of O2 over time.

The biggest problem would be calibrating the O2 analyzer. Normally, you calibrate it right before making a measurement.