A Method for the Measurement of Flatness of Polished Surfaces*
- 1 August 1940
- journal article
- Published by Optica Publishing Group in Journal of the Optical Society of America
- Vol. 30 (8) , 348-350
- https://doi.org/10.1364/josa.30.000348
Abstract
An optical method providing for the rapid inspection of extended surfaces is described. Two beams of parallel light are reflected by the sample through a cylindrical lens to form an astigmatic image of the source. If this image is a single line the surface is flat within the accuracy of the instrument. Radii of curvature in tested samples of the order of forty feet can be readily detected. An inspection device for testing glass to be used for photographic purposes is now in service.Keywords
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