高精度音響インピーダンス測定装置
1964 年 33 巻 3 号 p. 182-188
詳細
1964 年 33 巻 3 号 p. 182-188
This paper describes an apparatus for measuring accurately the acoustic impedance of foamed polymers by the standing wave method in the region between 160 and 3200 c/s.
This apparatus is designed and constructed so as to satisfy the following requirements: (i) The measurement of position of the probe tube must be accurate at least to 0.1mm; (ii) the measure-ment of standing wave ratio must be accurate to about 0.1 dB.
From measurement made on some samples of foamed polymers, the real and imaginary parts ofjthe acoustic impedance are calculated with an accuracy of about 2% in error.
This apparatus can also measure the sound absorption coefficient and is very useful for the study of the sound absorbing mechanism of foamed polymers.
Some typical results of the measurement are shown.
