| Zugriffsnummer | 20512 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Influence of the static pressure on the sensitivity of quarter-inch condenser microphones |
| Autor(in); Institution |
Fedtke, Thomas; 1.6, Schall, PTB-Braunschweig
Bouaoua, Nourreddine; PTB-Braunschweig, formerly
Brandt, Manfred; 1.6, Schall, PTB-Braunschweig
|
| Quelle/Jahr | Fortschritte der Akustik - DAGA 2007 : 33. Jahrestagung für Akustik:(2007), 831 - 832 |
| Availability | [CD-ROM] ; file name:data\\articles\\000227.pdf |
| Herausgeber(in) |
Mehra, Schew-Ram
|
| ISBN | 978-3-9808659-3-7 |
| Verlag | Berlin: Deutsche Gesellschaft für Akustik e.V. |
| Konferenzangaben | 33. Deutsche Jahrestagung für Akustik, Stuttgart, 19-22, March, 2007, Germany |
| Zusammenfassung | The sensitivity of condenser microphones depends on the environmental conditions (static pressure, temperature and humidity). They influence the acoustic properties of the air between the diaphragm and the back-plate of the condenser microphone. For a precise and repeatable free-field reciprocity calibration of condenser microphones, the measurements should be carried out in a controlled environment (23 °C and 101.325 kPa). Because of the non-controlled static pressure inside the anechoic room, a microphone sensitivity correction for the changes in static pressure is required. Those corrections are a function of frequency. The pressure sensitivity coefficients for quarter-inch condenser microphones type Brüel and Kjær 4939 were determined inside a closed pressure vessel, over the barometric pressure range from 90 kPa to 106 kPa, by using the electrostatic actuator method. The maximum static pressure coefficient was 0.2 dB/kPa at 95 kHz. An empirical equation for the static pressure coefficient as a function of frequency for this type of microphone has been developed. |
