TY - GEN

T1 - A practical implementation of microphone free-field comparison calibration according to the standard IEC 61094-8

A1 - Barrera Figueroa,Salvador

A1 - Torras Rosell,Antoni

A1 - Rasmussen,Knud

A1 - Jacobsen,Finn

A1 - Cutanda-Henríqueze,Vicente

AU - Barrera Figueroa,Salvador

AU - Torras Rosell,Antoni

AU - Rasmussen,Knud

AU - Jacobsen,Finn

AU - Cutanda-Henríqueze,Vicente

PB - Acoustical Society of America

PY - 2012

Y1 - 2012

N2 - An international standard concerned with the calibration of microphones in a free field by comparison has recently been published. The standard contemplates two main calibration methodologies for determining the sensitivity of a microphone under test when compared against a reference microphone. The two methodologies assume that the two microphones are exposed to the same sound pressure. This can be achieved by measuring the ratio of output voltages either sequentially or simultaneously. The first method requires a stable source to ensure that the sound pressure is approximately the same when the reference and test microphones are measured, whereas the second requires a source with a symmetrical directivity that ensures that the microphones placed at opposite positions are subjected to the same sound pressure. The two methods have been investigated experimentally in an extended frequency range. A third method, consisting of a combination of the sequential and simultaneous methodologies, has also been investigated. Though the application of time selective techniques is not discussed, the experimental results indicate the immunity to unwanted reflections in the sequential and combined approaches while it may be necessary to apply these techniques in the simultaneous approach.

AB - An international standard concerned with the calibration of microphones in a free field by comparison has recently been published. The standard contemplates two main calibration methodologies for determining the sensitivity of a microphone under test when compared against a reference microphone. The two methodologies assume that the two microphones are exposed to the same sound pressure. This can be achieved by measuring the ratio of output voltages either sequentially or simultaneously. The first method requires a stable source to ensure that the sound pressure is approximately the same when the reference and test microphones are measured, whereas the second requires a source with a symmetrical directivity that ensures that the microphones placed at opposite positions are subjected to the same sound pressure. The two methods have been investigated experimentally in an extended frequency range. A third method, consisting of a combination of the sequential and simultaneous methodologies, has also been investigated. Though the application of time selective techniques is not discussed, the experimental results indicate the immunity to unwanted reflections in the sequential and combined approaches while it may be necessary to apply these techniques in the simultaneous approach.

BT - INTER-NOISE 2012 Proceedings

T2 - INTER-NOISE 2012 Proceedings

ER -