麥克風互換校正之電性轉移阻抗量測技術

The Measuring Technique of Electrical Transfer Impedance in the Reciprocity Calibration of Condenser Microphones

陳兩興 ； 盧奕銘

《中華民國振動與噪音工程學會論文集》 1998 (1998/05) Pp. 161-164

https://doi.org/10.30028/CSSVANNUAL.199805.0161

摘要

聲量最高標準是麥克風的靈敏度，而麥克風靈敏度的軍位”mV/Pa”是一個導出單位。不同於以標準實體測得之單位，乃是用一量測方法而測得之。即利用電容麥克風具有的可逆互換特性及藉由電容麥克風的空氣轉移阻抗之量測，而將空氣中的麥克風靈敏度量測出來。
在所有的量測參數中，電性轉移阻抗的準確度對麥克風靈敏度的最後量測結果影響甚大，因此量測技術發展中心為精確地量測電性轉移阻抗，最近建立一種新的量測方法。本文即針對此一新量測方法加以說明，並比較舊有的量測方法而將所得之經驗作一敘述。

並列摘要

It is generally recognized by the world that the standard of sound pressure is realized through the calibration of standard condenser microphones by the reciprocity method. The microphones can be paired in three ways, and for each pair the microphones are coupled together in a closed coupler. One is driven to transmit and the other used as a receiver, sad the ratio of the open circuit output voltage of the receiver microphone to the input current of the transmitter microphone is measured. This electrical transfer impedance, together with knowledge of the acoustical transfer impedance of this coupled microphones, allows the sensitivities of microphones may be obtained.
In the result of microphone sensitivities, acoustical transfer impedance is the most effective factor in all of parameters. For enhance the precision of measuring, CMS has built anew method for measurement of electrical transfer impedance. This paper presents the new technique and compares its characteristic with method of yore.