高声强下传声器灵敏度校准

本文对CH16和BK4136等型号的电容传声器在高声强声波作用下,其灵敏度变化作了估算和校准。用BK4221型高声压传声器校准器对上述型号的传声器作灵敏度校准,声压级从140dB至161.6dB,这些传声器之灵敏度变化一般不超过0.3dB。与活塞发生器校准结果比较,两者最大差值一般在0.4dB之内。另外,在168dB至173dB的高声强环境中做了类似实验,结果一致。实验结果和理论分析相符,证实了用活塞发生器校准得到的传声器灵敏度值,来校准高声强(声压级在170dB以下)是可行的,这对高声强测试工作提供了方便。     

电容传声器耦合腔互易校准

本文对直径为24毫米和12毫米的国产传声器系列,建立起耦合腔互易校准装置.在BK4119型校准仪的基础上,作了若干改进.对读数系统和稳定振荡器输出采取了措施,使建立的校准系统的装置误差不大于±0.05分贝.达到国际标准IEC327的要求.     

MICROPHONE SENSITIVITY CALIBRATION UNDER HIGH INTENSITY SOUND

In this paper,the change of sensitivity of the condenser microphones CH 16 and BK 4136 etc.Was estimated.The microphones were calibrated under high intensity sound.The sensitivity ofthe microphones described above was calibrated with the high pressure microphone calibrator Type4221;the range of the sound pressure level was from 140 dB to 161.6 dB.In general,the maximumchange of sensitivity for these microphones is less than 0.3 dB.As compared with the rsults ofpistonphone calibration,the maximum difference is less than 0.4 dB,which is within the limits ofexperimental error.In addition,similar experiments were carried out under high intensity soundfrom 168 dB to 173 dB and the same results were obtained.The experiment results are in agree-ment with the results of the theoretical analyses.This method has proved that the microphone-sensitivity calibrated with a pistonphone can be used for the measurements of the high intensitysound(sound pressure level below 170 dB).This result is very useful in high inten