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. 16, 1993
Filed:
Nov. 27, 1991
Annie Tissier, Saint Ismier, FR;
Jean-Francois Teissier, Voiron, FR;
France Telecom (CNET), Paris, FR;
Abstract
A method for measuring the viscosity of a material consists in forming an array of parallel strips of material for constituting a diffraction grating; illuminating the array with a monochromatic light beam which produces a diffraction grating comprised of a main light spot (5) and of a plurality of adjacent diffraction spots, the envelope of which exhibits a major lobe (LO) including the main spot (5) and minor lobes (L1, L2); subjecting the array to a thermal process consisting in rapidly heating it at a predetermined temperature (T) and maintaining it at such temperature; selecting the brightest spot (6) among those of the first lobe (L1) and measuring the evolution of its light intensity (HL1) during the thermal process; determining the time interval elapsing until the first passage by a minimum intensity value (HL1b) of the spot (6); and deducting therefrom the value (.nu.) of the viscosity of the material constituting the array by the formula 1/.nu.=.alpha.d.