Re: [ATM] Sphereometer accuracy

["Bob May" <bobmay@nethere.com>]

Depends upon the size of the balls and the curve being measured.
I' ve got 1/32" diameter balls on the feet of the spherometer
that I've been suing and they will take a very steep curve in
order to become anything significant error of the ROC measuement.
As a result, I use the short version of the formula for working
with the typical focal length optics.
Finally, I use spherometers for getting a very quick measurement
of the ROC as an approximation while grindiing and use the
Foucault test for accurate measurements of the ROC of a mirror.
Bob May
bobmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
Replace the obvious words with the proper character.

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