Author(s): Wittstock Volker, Schmelzer Martin
The airflow resistance is a major acoustic parameter of porous materials. For the use as a damping element in cavities, a certain range of airflow resistances is prescribed by DIN 4109, the major standard for sound insulation in buildings in Germany. The measurement of airflow resistance is standardised in EN 29053. This standard comprises two different methods, the constant flow method and the alternating airflow method. At PTB, a new measurement device has been set up for the latter method which enables measurements at frequencies between 0.5 and 6 Hz. This is a major improvement compared to the majority of today's setups which run at a constant frequency of 2 Hz. In the contribution, the new measurement setup is introduced, the theoretical background of the method is given, the uncertainty is calculated and results of test measurements are reported.
Name: Dr Volker Wittstock