Velo Software

In-situ Absorption software

The microflown sensor allows to measure the acoustic properties of materials in situ using the in-situ absorption setup. There is no requirement for a special measurement environment, or a Kundt's tube (though the software supports measurements in a Kundt’s tube). The impedance software offers a complete solution for measurements of in situ impedance, as well as sound absorption and reflection coefficients.

The structure of the software is very user friendly. It is based on a measurement “tree” concept, where you can keep track of all tested material samples, thus allowing to compare and export as many different samples as you need. Furthermore, the workflow within the software is organised in tabs. Each tab constitutes a different step in the measurement chain. The process begins with the hardware setup. Afterwards, in the “capture” tab, you need to define whether you will take your measurements with the Impedance gun, or use a standing wave tube. Once you’ve made your choice, the acquisition of data over a material sample can begin. Analysis of the recorded data along with all calculations required to compute the absorption and reflection coefficients, is carried out through the tools available in the “Analyse” tab. Comparing, averaging or exporting of multiple data sets is done thanks to the features available in this tab. Finally, you can always create a report out of all gathered data by using the report “tab”.

Take a short tour of the in-situ absorption software following this short video:



  • Velo 4A | In-situ Absorption


  • FFT
  • Coherence
  • Transfer function
  • Noise generator: white noise, sine, chirp
  • Auto range
  • Impedance
    • Magnitude
    • Phase
  • Reflection
    • Magnitude
    • Phase
    • Imaginary
    • Real
  • Absorption
  • Impulse response function
  • Model calculation
    • Plane wave
    • Mirror source
    • Q-term
  • Octave
  • 1/3 Octave
  • 1/12 Octave
  • Filter for reflection cancellations
  • Export option to MS Excel / TXT


  • Characterization of materials
  • Can be used for:
    • Product development
    • End of line control before and after assembly