Re: ATM A question about Foucault testers

["Michael P. Lindner" <mikel@worldnet.att.net>]

Brandon Mathew wrote:
> 
> I'm starting to wonder about how I've set up
> the tester.  Should the numbers increase or decrease as the knife edge
> gets further from the surface of the mirror? 

Yes, the numbers should INCREASE as the knife edge gets FARTHER from
the mirror's surface.  When you do your data reduction, be VERY careful
of the units you are using.  Remember to put the decimal point in the
right place when you convert your tester's readings into inches (or mm
or cm).  Remember to use the radius of curvature, NOT the focal length
in the computations.  You did not mention what (if any) software you
are using to reduce the data.  You can get my "Tex" program, or Jim
Burrows "Foucault" program from my home page http://home.att.net/~mikel
if you would like.

--
Mike Lindner