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Free-field calibration of the pressure sensitivity of microphones at frequencies up to 80 khz
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Elbing, Brian R. Herring, G. C. Zuckerwar, Allan J. |
| Copyright Year | 2006 |
| Description | A free-field (FF) substitution method for calibrating the pressure sensitivity of microphones at frequencies up to 80 kHz is demonstrated with both grazing and normal incidence geometries. The substitution-based method, as opposed to a simultaneous method, avoids problems associated with the non-uniformity of the sound field and, as applied here, uses a 1/2 -inch air-condenser pressure microphone as a known reference. Best results were obtained with a centrifugal fan, which is used as a random, broadband sound source. A broadband source minimizes reflection-related interferences that often plague FF measurements. Calibrations were performed on 1/4-inch FF air-condenser, electret, and micro-electromechanical systems (MEMS) microphones in an anechoic chamber. The accuracy of this FF method is estimated by comparing the pressure sensitivity of an air-condenser microphone, as derived from the FF measurement, with that of an electrostatic actuator calibration and is typically 0.3 dB (95% confidence), over the range 2-80 kHz. |
| File Size | 80057 |
| Page Count | 30 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20080014269 |
| Archival Resource Key | ark:/13960/t2v45pt69 |
| Language | English |
| Publisher Date | 2006-01-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Microelectromechanical Systems Anechoic Chambers Sensitivity Broadband Calibrating Grazing Incidence Sound Fields Gas Pressure Acoustic Frequencies Electrets Sound Pressure Microphones Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
