If that's the sort of accuracy you require for camping situations, ................. .  'nuff said.

---- Mike S <mikes@FLATSURFACE.COM> wrote:
> At 07:04 PM 3/9/2010, Al Knoll wrote...
> >So in my vanagon, if the inside temperature of the air is 85deg
> >(jonesin for
> >spring, here) and a block of ice is melting what temperature is the
> >water
> >that is on the surface of the ice?  Oh yeah, at 60'ASL here in
> >downtowncowtown.
>
> Nowhere close to 0 C, depending on what you consider accurate. To get
> close to 0 C, you need shaved ice, made of distilled water, saturated
> with liquid, but not floating in liquid water. That, in a well
> insulated container, will get you within millidegrees of 0 C.
>
> Reference:
> http://ts.nist.gov/MeasurementServices/Calibrations/upload/SP819.PDF