[aprssig] Balloon- clear package keeps warm

[Jason KG4WSV]

On Tue, May 6, 2014 at 9:59 AM, Robert Bruninga <bruninga at usna.edu> wrote:
> Triple layered plastic went no lower than 15 C (60F)
>
> Dual layered plastic went no lower than – 15 C (5 F)
>
> Single layered plastic went no lower than -27 C (-17 F)
>
> While the outside temperature went to -60 C (-76F)
>
>
>
> Actually, I guess the triple layer is more like 4 layers since the internal
> layer was bubble wrap.


Most commercially available boards (e.g. arduinos, spark fun,
adafruit, etc) use commercial temperature rating components, which are
good to 0C (and I've seen them fail on flight at temperatures not much
lower than that).

Unless I build custom boards with industrial/automotive/military
temperature rated components, I have to use a large amount of material
that isn't particularly suited to making enclosures.

Or I can make a foam box, with a lid, easy to work with.  Foam also
makes it ridiculously easy to meet the cross sectional density
requirement for no-waiver unmanned free balloons.

-Jason
kg4wsv