Re: [ATM] Sphereometer accuracy

[Guy Brandenburg <gfbrandenburg@yahoo.com>]

If you really, really need the convex and the concave to match each other very, very closely, then all you need to make sure that happens is a monochromatic light source; put one on top of the other; illuminate; and look at the interference bands. Then interpret them.
Guy

"Richard F.L.R. Snashall" <rflrs@rcn.com> wrote: Dominic-Luc Webb wrote:

>
>of 
>
>>paper and a light source. 
>>
>
>Yup, +/- a mm or so... I have thus far survived. I have not 
>yet worked a scope that had specs that could not tolerate 
>an actual ROC that differed from the specs by this amount. 
>Have a lot of (any) ATMs encountered such extreme requirements?
>
>Regarding convexes, I simply measure the tool, which 
>should be a very close replica.
>
We already have.  The tolerance suggested by Newport Glass for their
doublets is 1 part in 2000.  The six inch model has internal radii
on the order of +/-800 mm.  Assuming that tolerance level to be
correct, it works out to be +/-0.4 mm on the RoC -- a bit tighter.
_______________________________________________
ATM mailing list http://www.atmlist.net/



Guy  Brandenburg
Washington, DC
My home page:
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
_______________________________________________
ATM mailing list http://www.atmlist.net/