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Impedance Tube Systems

Impedance Tube - Description:

Impedance Tube can accurately measure sound absorption coefficients and impedance according to both ISO and ASTM standards. They also support the sound transmission loss measurements based on the Transfer Function Method. The Transfer Function Method separates the incident and reflected energy from the measured transfer function, and then estimates the acoustic properties of the tested sample installed in the tube.

The SW series Impedance Tubes are specially designed not only to work with the cut samples, but also for direct use in the field. The small size and durable aluminum construction make it easy to be transported and used for estimating the properties of walls, ceilings, installed building materials, road surfaces, different ground surfaces, interiors of vehicles, and etc. BSWA offers the complete set of Impedance Tube system, which includes: the tubes, microphones; DAQ hardware and measurement software.

BSWA 1/4’’ microphones MPA416, which have excellent phase matches, are ideal for impedance applications. The microphones are directly connected to optional 2-channel MC3522 or 4-channel MC3242 data acquisition hardware. PA50 power amplifier is used to drive the loud speaker in the impedance tube. The BSWA VA-Lab software provides all measurement functions for sound absorption and transmission loss testing.

Impedance tube transport case SW422 and SW477 with 4 MI19 measuring microphones and microphone calibrator CA114

Impedance tube kit for acoustic material testing

Conforms to the following standards:
  • ISO 10534-1: 1996 Acoustics-Determination of sound absorption coefficient and impedance in impedance tubes-Part 1: Method using standing wave ratio.
  • ISO 10534-2: 1998 Acoustics-determination of sound absorption coefficient and impedance in impedance tubes-Part 2: Transfer function method.
  • E 1050-08 Standard test method for impedance and absorption of acoustic materials using a tube, two microphones and digital frequency analysis.
  • E 2611-09 Standard test method for measuring sound transmission at normal incidence of acoustic materials based on the transmission matrix method.

The transmission loss is based on the transfer function method with four microphones, and the ISO standard.
The impedance tube system was developed on BSWA’s digital acquisition hardware with LabVIEW development platform.

SW420R impedance tube for measuring the sound absorption properties of road surfaces

SW420R impedance tube for measuring the sound absorption properties of road surfaces

SW420R is designed according to ISO 13472, so that a method of measuring the sound absorption properties of road surfaces can be carried out on site with impedance tube.

This method allows the sound absorption characteristics to be evaluated without damaging the surface.

The test results can also be used to qualify the absorption properties according to ISO 362 and ISO 18044.

The use of SW420R and the algorithm is the same as described in ISO 10534 (equivalent to GB/T 18696), VA-Lab IMP module can be used directly with this product.

  • Specially designed for the measurement of sound absorption characteristics of road surfaces
  • Integrated design, portable and stable
  • Selected sealing material, reduces leakage of sound signal
  • Download SW420R User Manual

Measurement setup of the impedance tube

Calibration of the
impedance tube measuring chain

Sound absorption measurement

impedance tube
Impedance Tube kit
Model
Impedance tube prices without accessories
Euro
+
VAT
SW420
For accurate measurement of sound absorption coefficient
(63-1800Hz), 100mm inner diameter. Tube with 100mm diameter 100mm diameter sample holder
11700 €
SW470
For accurate measurement of sound absorption coefficient(1800-63000Hz), 30mm inner diameter. Tube with 30mm diameter 30mm diameter sample holder
9900 €
SW422
For accurate measurement of sound absorption coefficient
(50-1800Hz) and material impedance values(63-1800Hz)100mm inner diameter.
– 100mm diameter tube
-Sample holder with 100mm diameter
-100mm diameter extension tube
13100 €
SW477
For accurate measurement of sound absorption coefficient
(1600-6300 Hz) and material impedance values(1600-6300 Hz) 30mm inner diameter.
– 30mm diameter tube
– Sample holder with 30mm diameter
– 30mm diameter extension tube
11800 €
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