[time-nuts] Voltage standards

[David Forbes]

At 4:23 PM -0800 11/30/08, Lux, James P wrote:
>Exactly.. I'm sure I'm not the only one on this list that has 
>contemplated home use of liquid helium or even making the stuff. 
>Hey, if Onnes could do it 100 years ago, so can we.
>
>I assume the cryogen isn't being used for superconductivity in this 
>case, but for just being cold.  In which case, perhaps LH2 or LN2 
>would serve almost as well.  The latter, particularly, is pretty 
>manageable (i.e. You don't have to make it yourself).
>
>Cost wise, I like the snippet I read in Scientific American a decade 
>or so ago.. LN2 is the cost of milk, LHe is the cost of fine scotch 
>whisky
>Is a obsessive precision worth a bottle of scotch?
>
>Jim

I work in a lab where LHe is around much of the time. So it's not 
that far of a stretch for me to contemplate using it, although I 
don't personally handle the stuff.

We also have a few obsolete receiver Dewars lying around... one of 
them could be retrofitted to hold a cryogenic standard if we felt 
like it.

But there's the "rent" of regularly buying that LHe to keep the 
standard cold. Kinda like being a drunkard on fine Scotch whisky 
without the buzz.

-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/