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. 20, 1990
Filed:
Mar. 24, 1988
Richard H Hoops, Stoughton, WI (US);
Larry J Eriksson, Madison, WI (US);
Mark C Allie, Oregon, WI (US);
Nelson Industries, 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 a downstream end of the tube. At least a portion of the length of the tube is composed of a rigid foraminous material containing a multiplicity of interconnected cells with the average cell size being less than 100 microns. In operation sound pressure fluctuations cause pressure waves to propagate through the cells to the inside of the tube and the sound pressure waves add constructively to create a high pressure sound at the microphone, while turbulent flow pressure fluctuations are essentially averaged out.