Re: Filament resistance

["Daniel L. MacIsaac" <Dan.MacIsaac@Nau.Edu>]

> You took the power dissipation when incandescent, and the Rho for room
> temperature. The temperature range is so large and somewhat non-linear too
> that this leads to large errors.
>
>  Jones & Langmuir published this:
> temp K    Resistivity (micro ohm cm) (NOTE UNITS)
> 300       5.65
> 1000     24.93
> 2000     56.67
> 3000     92.04
>
> (If you feel this critique is cogent, perhaps you would write the 
> publishers, as a public-service.)
>
> Whatcott    Altus OK
Brian,

Thanks for the improved rho values; I appreciate your effort finding them
and setting the record straight (por improving it).  It'd still be nice to
have a geometric determination of the length of that wire spiral as well.

I agree with your and Leigh's comments.  I'd feel happier if I knew the WHOLE
picture, including a correct temp for the filament (is 3000K the photo
standard?) and a better value on the diameter of the filament.  As well, the
composition of the filament -- is it really just W?

At that point I'd contact the publishers.  It'd be nice to suggest a complete
appropriate (and cogent :^) correction at once.

Dan M