Acoustic primary calibration of microphones under free-field conditions is performed by reciprocity, using microphones in pairs, one working as emitter and the other as receiver. The microphones are placed in an anechoic chamber. Considering the extreme accuracy required in this kind of measurement, every minute detail of the setup must be considered. In this framework, numerical modeling of the inside of the microphones and the outside domain can provide important clues for understanding the behavior of the system and finding ways of improving its performance, that is, reducing its uncertainty. This is especially needed at high frequencies, where the diaphragms have a complex movement and the wavelength becomes comparable to the size of the microphones. The usual assumptions, such as considering the microphones as point sources, are invalid in that range. The paper will deal with a coupled numerical implementation of this kind of measurement, taking into account the internal losses in the microphone, the diaphragm movement and the coupling with the exterior.
|Title of host publication||Proceedings of Inter-Noise 2003 : http://www.i-ince.org/|
|Number of pages||6|
|Publisher||The International Institute of Noise Control Engineering|
|Publication status||Published - 2003|