Dry cave bad air

[ianr33]

-it will still read PO2 and you body relys on PO2 in order to get enough oxygen. Hence even if it was a higher ambient pressure and a lower oxygen fraction as long as you get an PO2 reading above 0,16 bars you will not encounter an oxygen issue in the dry passage.

Unless you have an air pocket in a deep cave , and get a pO2 of, say, 2.0! No idea if any such place actually exists or not ?

[Nitrogenius]

Unless you have an air pocket in a deep cave , and get a pO2 of, say, 2.0! No idea if any such place actually exists or not ?

Yes ok.. theoretically you might also have a cap to watch not only a floor..
But their would either have to be an extremely high fraction of O2.. Of which I would have trouble explaining where it should stem from..
or extremely high pressure i.e. past the old 66m/216 feet in water column..
I guess in such caves you could also check for high Po2 if you meet a gas pocket..

[Walter Pickel]

Phillip,

When we found some of these near Bayahibe, we took a lighter to test the air. Not sure what depths you are hitting but a very dry box / bag should do the trick to transport the lighter / matches.

Walter

[nimoh]

wouldn't the lighter test be a little dangerous if the pocket was a mix of methane and oxygen?

[jason]

wouldn't the lighter test be a little dangerous if the pocket was a mix of methane and oxygen?

High concentrations of methane are more of an issue in coal mines. While it is not impossible to have high concentrations of methane in a cave, it is so unlikely that I don't worry about it. I would consider the likelihood of blowing yourself up in a cave by using a lighter to be similar to being struck by lightning. Cavers regularly used open flames as a light source until LEDs more or less made them obsolete (I still miss carbide though, because it was a nice way to warm things up - including lunch and your freezing cold body)