28 May 1980 Optical Open-Area Ratiometer
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Proceedings Volume 0220, Optics in Metrology and Quality Assurance; (1980) https://doi.org/10.1117/12.958583
Event: 1980 Los Angeles Technical Symposium, 1980, Los Angeles, United States
Abstract
An optical method for measuring the percent of open area of perforated sheet materials is presented. The technique, which is based on Fourier optics, uses a detector to measure a small central portion of the light in the Fraunhofer diffraction pattern of-the perforated sheet. This approach offers accuracy and speed while avoiding diffraction problems associated with arrays of small holes. In addition it can be used with translucent materials. A brief theoretical analysis is presented as well as results obtained with a laboratory system. The system is being developed to inspect perforated materials fabricated for use on noise suppression systems for aircraft engines, however, it should be useful in the general noncontact determination of the open area of perforated materials.
© (1980) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Fred M. Dickey, Fred M. Dickey, Mark A. Petersen, Mark A. Petersen, } "Optical Open-Area Ratiometer", Proc. SPIE 0220, Optics in Metrology and Quality Assurance, (28 May 1980); doi: 10.1117/12.958583; https://doi.org/10.1117/12.958583
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