The High Flow Resistance Meter (HF SIGMA) is designed to provide reliable measurement of resistivity, resistance, standard resistance and permeability to airflow as a function of flow velocity for a wide range of open cell materials used for noise control.
The flow velocity ranges from 10 cm / s up to 280 cm / s for a 100 mm diameter sample (the speed depends on the atmospheric conditions) and the measured pressure loss can go up to 17 kPa.
Measured Properties in Function of Flow Velocity
1. Pressure drop (Pa)
2. Airflow resistance (Pa.s/m or rayls)
3. Normalized airflow resistance (normalized by air characteristic acoustic impedance)
4. Airflow resistivity (Pa.s/m² or rayls/m)
5. Viscous permeability (m² or Darcy)
Mecanum’s high airflow resistance meter is used by the world’s leading material suppliers for both automotive and aircraft industry for quality control in the manufacturing process of materials; research, development, and innovation, and for feeding acoustical prediction software dealing with sound absorbing materials, perforated plate, fabrics for a high sound pressure level application.
The system includes:
Two specimen holders* (100-mm and 44.44-mm diameter)
*other sizes available
Thin film holder
Certified calibrated resistance
Grids to support limp material
Rings to minimize airflow leaks around the sample
The SIGMA-X software fully controls the measurement and calculates the main properties and statistics related to the measurement. It corrects pressure and temperature. The system works with disc shaped samples.