In-situ Absorption

Acoustic noise pollution can be reduced by absorbing sound energy. Absorbing material packages are used in many applications to attenuate sound. Knowing exactly the acoustic properties of your materials and the effectiveness of the applied material packages is a requirement to successfully reduce noise levels. The In-situ absorption setup is a solution to achieve just that.



For more information on In-situ Absorption or to request a quote, contact our team now:


With a small, handheld impedance gun the acoustic absorption, reflection or impedance can be measured in just a few minutes, broad band and under normal and oblique angles. With a sound source at 23cm from the probe, noise is generated towards the sample. The impedance gun is equipped with a system designed to decouple the sensors from structure born vibration generated by the spherical loudspeaker. The sound pressure and acoustic particle velocity are measured directly on the surface of the material. The absorption & reflection coefficient can be obtained directly from the measured impedance as the complex ratio of sound pressure to particle velocity.

Destructive testing of samples is no longer required. Sound absorption can be measured under any angle of incidence. The high spatial resolution that the system provides, enables the analysis of inhomogeneousmaterials, e.g. jet liners. In addition to material samples, curved materials and complete assembled parts can be tested. As the in situ method also works with relative movement between sample and probe, end of line control for materials or complete acoustic packages is made possible.

Applications include:

  • Material sample testing
  • EOL Quality Control
  • Component testing
  • Trim package validation


  • Frequency range 300Hz – 10kHz
  • In situ method – Measurement of:
    · Impedance
    · Sound reflection coefficient
    · Sound absorption coefficient
  • Non-destructive testing method
  • Flat & curved surfaces
  • Homogeneous & inhomogeneous materials


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