Microphone probe for acoustic measurement in turbulent flow
US4811309A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1987 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Sep 4, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.