X射线衍射法测量电容传声器的膜片张力

Measurement of Diaphragm Tension of Condenser Microphoneby X-ray Diffraction

为满足电容传声器膜片张力的直接测量需求,利用X射线衍射法对处于不同张力大小的电容传声器膜片进行测量,并与静电激励谐振法的张力计算值进行比较。结果表明,两者呈现相同的趋势并具有较好的一致性。通过传声器频率响应计算得到的谐振频率包含了电容传声器膜片后空腔等结构部件的影响,其测量值略高于膜片自由振动的谐振频率,因此X射线衍射法的测量结果略低于根据谐振频率计算的张力值。最后通过系列试验进一步验证了膜片张力对电容传声器电声特性的影响。

To realize the direct measurement of the diaphragm tension of condenser microphones,the X-ray diffraction technology is adopted to measure microphone diaphragm with different tension.Comparing with the calculated tension value of the electrostatic excitation resonance method,the results show that two methods had the same trend and good consistency about the tension of microphone diaphragm.The resonant frequency calculated by the microphone frequency response includes the influence of the back cavity of the condenser microphone.Therefore,its measured value is slightly higher than the resonant frequency of the diaphragm itself.Therefore,the measured result of the X-ray diffraction method is slightly lower than the tension value calculated according to the resonant frequency.Finally,the influence of diaphragm tension on the electroacoustic characteristics of condenser microphone is verified by a series of tests.