Re: Heating tape

[herbgottlieb@juno.com (Herbert H Gottlieb)]

On Sat, 10 Oct 1998 08:25:12 -0500 brian whatcott <inet@intellisys.net>
writes:

> I was not enthused. For copper, alpha is 16.7E-6 per K
> so a 10 cm specimen raised 1K moves 1.67 microns
> or roughly 3 wavelengths.  A visible interference difference looks for a
quarter wave change. Can you reliably and uniformly heat a specimen in
0.1K steps?
> brian whatcott <inet@intellisys.net>
> Altus OK
I do not understand why it is necessary to heat a specimen 
in 0.1K steps. If a 10 cm specimen is heated slowly and 
uniformly from room temperature to 30 degrees above room
temperature, there should be no problem counting the 
45 fringes that shift during the heating process.

Using copper heat pipe sounds interesting. Any idea of the 
cost of a 20 cm length?? Where can such a sample be obtained??

Herb Gottlieb from New York City
(Where our local plumbing stores carry heat tapes)