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Sound in air

Working group 1.61

Realization and dissemination of the sound pressure unit (Pa)

The realization of the unit of sound pressure, Pascal, by means of the reciprocity calibration of laboratory standard microphones (IEC 61094-2, 61094-3) traces the acoustical unit 'Pascal' back to mechanical and electrical quantities. According to the application of the microphones, the pressure sensitvity (e.g. for a microphone used in the ear canal of an ear simulator) or the free-field sensitivity (e.g. for a microphone used with a sound level meter) are measured with basically different measurement set-ups in the frequency range from 31,5 Hz to 20 kHz (pressure sensitivity) resp. 500 Hz to 30 kHz (free-field sensitivity).

For the dissemination of the unit 'Pascal' sound calibrators or condenser microphones, which themselves were calibrated by secondary procedures (eg. IEC 61094-5), are used (tracable to the national reference). See this page for microphone calibration offers in our section).