The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 02, 1988
Filed:
Oct. 14, 1986
Fu-Pen Chiang, Port Jefferson, NY (US);
Other;
Abstract
Two electro-moire systems provide strain values directly. By shifting a reference grating relative to a specimen grating along the direction perpendicular to the grating line the resulting moire fringes sweep across the field. In one method two photo-detectors are used to record the cyclic intensity signals. The phase difference between the two signals is used in a special formula for the calculation of strain. In the other method only one photo-detector is used, and the frequency information of the cyclic signal is used in another formula for the calculation of strain. The electrical signals from photo-detectors are converted into digital signals and processed using a digital computer through FFT (Fast Fourier Transformer) to eliminate noise. Strain-values as small as one microstrain can be measured.