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You are right, I answered this one to quick, mixing up triple point and inversion temperature. Inversion temp : At adiabatic expansion a gas cools down if below the inversion temperature. It heats up if above. Inversion temp for air is +490 °C, for Hydrogen -80°C, for Helium I have calculated it using van der Vaals coefficients to be 133 °K, that is -139°C. But pls. calculate yourself , for I cannot exclude any errors on my behalf. In short this means, in a real world , air will cool down in expansion , Hydrogen and Helium will heat up. In a mix , it is different, effects and temp will mix. ScottBonis@ao*.co* schrieb: > > Hi Mat, > > SAY WHAATTT???? I think you need to learn a little about the physics of > gasses. > > Take care and dive safe, Scott > > Some weeks it's just not worth the effort to gnaw through the restraints and > scramble up out of the pit. > > In a message dated 10/9/01 2:32:08 PM, mat.voss@t-*.de* writes: > << Jozef, > It could be the Joule thompson effect. There is some sort of "triple > point specific to each gas, each mix, which rules wether your gas heats > up or cools down when expanding, relative to the prssure you are > starting the relevant consideration. > regards > Matthias >> > > "Gliviak, Jozef" schrieb: > > Hello Guys, > > > > I've heard a story that some Polish guys were using about 20+ % of He in the > > mix in order to prevent regulator freezing during diving in very cold > > springs (1-3C)in High Tatra mountains. Is there any physical explanation of > > this behavior or it it just a old boys tale ? > > > > Best regards > > > > Jozef Gliviak > > Slovakia -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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