\underline{Description of the test facility:}\newline
Impedance tube made of aluminum with a 2 inch bore diameter. Specimen holder with an adjustable tubing end of a massive, sealed aluminum piston. Measurement tube with three microphone bores with a distance of 17mm and 110mm.
Probe microphone picking up the sound field at the center of the tube.
Evaluable frequency range: approx. 100 Hz - 8 kHz by suppressing the first tube mode. Broadband excitation by sine sweeps. Evaluation according to ISO10534-2 with the help of a FFT measurement technique developed at ITA.}\\
Impedance tube made of aluminum with a 2 inch bore diameter. Specimen holder with an adjustable tubing end of a massive, sealed aluminum piston. Measurement tube with four microphone bores, the distance from the first microphone position to the second, third and fourth are 17~mm, 110~mm and 510~mm, respectively. Probe microphone picking up the sound field at the center of the tube.
Evaluable frequency range: approx. 100 Hz - 8 kHz by suppressing the first tube modes. Broadband excitation by sine sweeps. Evaluation according to ISO10534-2 with the help of a FFT measurement technique developed at ITA.}\\