Investigation on the Effects of Air-Damping on the Sound Absorption Coefficients Measured in the Tube

관내법 시험시 Air-Damping이 흡음률에 미치는 영향 고찰

This paper raises issues in testing the absorption coefficients of sound-absorptive samples in the standing wave tube according to the Korean standard of KS F 2814. The code does not consider any effect of air-damping during test. This limitation has been shown to yield much variation of sound absorption coefficients for recent sample tests whose coefficients are less than 10 %. An improved method of calculating the sound absorption coefficients is proposed in this work and its effectiveness in real test is also illustrated. Finally, the guide line for the modification of our national standard code KS F 2814 is suggested for the future.