impedance tube 29mm

Description

Mecanum's impedance and transmission tubes are specially designed to measure key acoustic indicators of a wide range of materials using 2, 3 or 4 microphone methods. The three-microphone method is based on ASTM E2611 where unknown loads are replaced by known air cavities. The third microphone is inserted into the piston and is always exposed to maximum pressure for the best "signal to noise" ratio.

Standards & certifications

  • ASTM E1050

  • ISO 10534-2

  • ASTM E2611

Main advantages

  • Frequency range: 50-6600 Hz

  • Measurement method according to ASTM and ISO standards

  • Ease of use

  • Measurement method taken from the scientific literature

  • Durability

  • Measurement quality

Applications

  • Absorption measurement

  • Transmission measurement

  • Research and development

  • Comparative analysis

  • Quality control

  • Determination of the properties of open-cell porous materials by tube measurements and FOAM-X software. The obtained properties are the open porosity, static airflow resistivity, the tortuosity, the viscous and thermal characteristic lengths, the static thermal permeability and elastic parameters.

Included

  • An impedance and transmission tube with digital piston for thickness reading;

  • An anechoïc termination;

  • Microphones;

  • A 24-bits 4-inputs/1-output acquisition system with integrated audio amplifier;

  • TUBE-X measurement software;

  • A verification sample;

  • Grids to support flexible materials;

  • Rings to minimize acoustic leakage around the sample;

  • A carrying case;

Properties measured

2
mics

Absorption coefficient at normal incidence (α)

Complex reflection coefficient at normal incidence (R)

Normalized surface impedance (Zs/Zair)

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Normal incidence transmission loss (NSTL)

Normalized characteristic impedance (Z/Zair)

Wave number (k)

Equivalent dynamic bulk density (peq)

Equivalent dynamic bulk modulus (Keq)

Transfer matrix coefficients (Tij)

ASTM E1050 Standard

ISO 10534-2 Standard

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ASTM E2611 Standard

3
mics

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4
mics

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Frequency range

Tube
29 mm

Tube
44.44 mm

Tube
100 mm

Overall frequency range (Hz)

50 to 6600

45 to 4300

35 to 1800

Frequency range with large microphone spacing (Hz)

50 to 1600

45 to 2000

35 to 1600

Frequency range with small microphone spacing (Hz)

175 to 6600

115 to 4300

70 to 1800

Accessories

  • Circular cutter for porous materials

  • Porous material slicer

  • ENVIRO Station

  • FOAM-X Software

  • NOVA software

  • Resistive screen holder (44.44mm only)

  • Square specimen holder for metamaterials (44.44mm only)

Documents

Videos