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:
Mar. 07, 1989
Filed:
Sep. 04, 1987
Larry J Eriksson, Madison, WI (US);
Mark C Allie, Oregon, WI (US);
Richard H Hoops, Stoughton, WI (US);
Nelson Industries Inc., Stoughton, WI (US);
Abstract
A microphone probe for acoustic measurement in turbulent flow. The probe includes a tube having a closed end facing upstream with respect to the direction of sound propagation, and a microphone is located in the downstream end of the tube. The tube is provided with a plurality of small ports, or alternately a slit, that extend a substantial portion of the length of the tube and an acoustically resistive material is stretched across the ports and clamped to the tube. In one form of the invention, the side edges of the material are connected to rigid bars and the bars are drawn together by a plurality of threaded fasteners to stretch the material over the ports. The threaded adjustment of the fasteners provides a means for varying the acoustical resistance of the material. In a second form of the invention, the bars to which the side edges of the material are attached, are clamped together by spring clips.