[aprssig] Balloon warmth

[david Vanhorn]

  Bob is right, there's plenty of sun up there to keep you warm, just don't throw it away.



-- Sent from my Palm Prē
On Mar 24, 2010 9:02, Steve Noskowicz <noskosteve at yahoo.com> wrote: 







The sealed plastic pouch versions don't use air.  It is a reversible exothermic chemical reaction.  This is the ones with the metal popple disk.



I think they have a super saturated solution of an acetate salt, perhaps sodium acetate.  There's several YouTube videos showing the process - ad nausium...



at fractions of an inch of mercury the Iron compound versions will die.





-- 73, Steve, K9DCI





--- On Wed, 3/24/10, Scott Miller <scott at opentrac.org> wrote:



> About a dozen people have suggested

> this, but I'm not convinced the oxygen level is

> sufficient.  I do happen to have a vacuum chamber in

> the shop, so once I get a functioning payload again I'll

> have to throw a few of those in there and compare the heat

> generated to a control at 1 atmosphere.

> 

> Scott

> N1VG

> 

> AD4BL wrote:

> > An alternative to keeping equipment warm on a balloon

> flight is to use the hand warmers.   They

> last about

> > 8 hours and provide enough heat to keep equipment

> operating in a cold environment.

> > 

> 

> 

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