Mailing List Archive Mailing List Archive
On Mon, 1 Aug 1994, Roger Carlson wrote: > If I could remeber any pchem or physics, I could make more sense of this. > I think there is a cloud or a fog forming in your masks, which happens > whenever the temperature of a gas decends below the dew point of the gas for > its water content. Kind of a quick and dirty rule of thumb for cloud formation > is that the spread between the dew point and temperature drops 1 degree every > thousand feet, so if the ground air temp is 70 and the dew point is 60, you'll > have clouds forming at 10,000 feet. Similar things happen when moist air blows > over the ocean and hits a rise, like a hill on a shoreline. > Anyway, for some reason, the gas in your masks momentarily crosses the > dew point. Could be that the gasses are literally at different temps, which I > think is somewhat unlikely, could be some kind of stochiometric cooling due to > mixing, could be some kind of cooling due to the introduction of a gas with a > different rate of heat transfer to the outside, could be all those things. The > answer's in there somewhere. Like I said, wish I could remember physics. could be on to something... interested in others reply on this one.. i know that rich always carries his travel mixes with him, thus all gases would be the same temp, (we have a slight thermalcline at 270fsw here that gets your attention when you pass thru it) except his back-up o2 which is surface supplied (he has a *great* rig for those that are looking for ways to set their's up, it's been detailed in a few writings i'm sure he can point you in that direction) (btw rich, have you used your oms bc yet... we got ours friday, will trial them tuesday off dillingham). on my deeper dives (300+) we sometimes hang one of our back-up travel tanks on the line. (don't get excited, at least one of the buddy team has his\hers on board) ... could have something to do with the temp gradient. > As far as fog in that cave, trying to figure that out, too. Are you > sure it doesn't form when the surge goes out? that would mean that the volume > of trapped air was expanding. PV=nRT, so expansion means cooling, and cooling > means dipping below the dew point. > good question, i looked close to answer that for myself too... but will double check the video and get back to you. > > One quick note on glue: Elmer's makes a new kind of glue that is based on > clear silicon caulk, but it sets up very nicely into a strong, > gap-filling, flexible bond. Worth trying. > > > aloha, dennis
Navigate by Author:
[Previous]
[Next]
[Author Search Index]
Navigate by Subject:
[Previous]
[Next]
[Subject Search Index]
[Send Reply] [Send Message with New Topic]
[Search Selection] [Mailing List Home] [Home]