A PNEUMATIC APPARATUS FOR MEASURING THE FLATNESS OF PHOTOGRAPHIC PLATES
- 1 January 1956
- journal article
- research article
- Published by Maney Publishing in Survey Review
- Vol. 13 (99) , 208-212
- https://doi.org/10.1179/003962656792063024
Abstract
The paper describes a simple pneuluatic apparatus, working at a pressure of about ½lb./in.2, which enahles the flatness of photographic plates to be checked rapidly prior to their use in the camera. The errors of flatness are shown directly by the levels of coloured water columns in parallel manometer tubes; the magnification is 2,500 and the linear range is ±15μ (±0.0006 in.). The apparatus essentially measures departures from a prescribed form and has therefore other applications.Keywords
This publication has 0 references indexed in Scilit: