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.

© 1940 Optical Society of America

Photoelectric Measurement of Scale Marks and Spectrum Lines

George R. Harrison and Julius P. Molnar
J. Opt. Soc. Am. 30(8) 343-347 (1940)

A Multipurpose Photoelectric Reflectometer

Richard S. Hunter
J. Opt. Soc. Am. 30(11) 536-559 (1940)

Hue Saturation and Lightness of Surface Colors with Chromatic Illumination

Deane B. Judd
J. Opt. Soc. Am. 30(1) 2-32 (1940)

An Improved High Speed Recording Spectrophotometer

George R. Harrison and Edward P. Bentley
J. Opt. Soc. Am. 30(7) 290-294 (1940)

A Variable Focus Lens and Its Uses

Robert Graham
J. Opt. Soc. Am. 30(11) 560-563 (1940)