Microphone calibration method

Abstract

The invention discloses a microphone calibrator and a calibration method thereof. The microphone calibrator comprises a muffler, a mounting section for a microphone to be calibrated, a mounting section for a standard microphone and a sound source which are sequentially connected from front to back, wherein the mounting section for a microphone to be calibrated is provided with a mounting hole fora microphone to be calibrated, and the mounting hole is used for mounting the microphone to be calibrated; and the mounting section for a standard microphone is provided with a mounting hole for a standard microphone, and the mounting hole is used for mounting the standard microphone. The calibration method comprises the following steps: mounting two standard microphones in two mounting holes of the different standard microphones in accordance with different frequencies, measuring a complex reflection coefficient r of the muffler, and then obtaining a complex sensitivity curve of the microphone to be calibrated; and enabling the sound source to respectively send out sound waves of different frequencies, obtaining the complex sensitivity curve of the microphone to be calibrated, and thus achieving the purpose of calibrating the microphone to be calibrated. The invention can realize simultaneous calibration of a large number of microphones, thereby saving the calibration time. Besides, the invention can carry out phase calibration for a large number of microphones.

Description

technical field [0001] The invention belongs to the field of acoustic measurement, in particular to a microphone calibration device and a calibration method thereof. Background technique [0002] A microphone is a common sensor used to convert various acoustic signals into electrical signals. There are many kinds of microphones, but no matter what kind of microphone is used, it must be calibrated before use, especially when it is used as a measurement microphone. The traditional calibration method is to use a single-frequency sound source such as B&K4228 or B&K4230 for single-frequency amplitude calibration, which requires the frequency response of the microphone to have a very good linearity. Only in this way can the sensitivity of a single frequency be used as the sensitivity of the entire frequency range. Sensitivity is used. If you want to use some microphones whose frequency response curve is not flat enough, it is impossible to use this sound source for calibration. I...

AI Technical Summary

Problems solved by technology

The traditional calibration method is to use a single-frequency sound source such as B&K4228 or B&K4230 for single-frequency amplitude calibration, which requires the frequency response of the microphone to have a very good linearity. Only in this way can the sensitivity of a single frequency be used as the sensitivity of the entire frequency range. Sensitivity is used. If you want to use some microphones whose frequency response curve is not flat enough, it is impossible to use this sound source for calibration. In addition, when using a large number of microphones, the traditional calibration device can only be calibrated one by one, which is very time-consuming; In addition, many measurement applications require that the phase of the microphones used can be well matched, and the current calibration equipment cannot provide the phase calibration of the microphones

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