• Measurement kit for acoustical complex properties testing (3Mics_MAA)
  
• Measurement kit  for Transmission Loss testing (4Mics_MAA)
• Measurement kit for airflow resistivity testing (Resistivity_MAA)
• Measurement kit for open porosity testing (Porosity_MAA)
  
• Measurement kit for tortuosity testing (Tortuosity_MAA)
• Measurement kit for dynamic stiffness testing (Rigidity_MAA)
• Measurement kit for mechanical properties testing by means of a resonant method (Resonat_MAA)
• Measurement of sound absorption properties of road surfaces in situ Spot method for reflective surfaces (ISO 13472-2)
  
  
  

Measurement kit for open porosity testing (Porosity_MAA)

Porosity is a measure of the fractional amount of air volume within the porous material. Porosity_MAA permits the measurement of the open porosity by means of a method based on Boyle’s Law, using isothermal compression of air volume within and external to the materials.



Parameters
Open porosity.

Technical specifications
Measurement procedures: Pressure variation in the measurement chamber during the entire process.
Measurement chain:

• Pressure transducers;
  
• DC/AC Acquisition system (NI USB-9215A);
  
• Software developed in Labview®.
  

Applications
The open porosity value can be used both to understand the internal structure of a porous media and to make possible the use of adavanced predition models for the determination of complex acoustical parameters when these are not experimentally measured.


References
F. Pompoli, P. Bonfiglio, Apparecchiatura per la misura della porosità di materiali a cella aperta, ATTI 34° Convegno AIA, Firenze 13-15 Giugno 2007.
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