Sound Transmission Loss Testing
Description
Sound Transmission Loss Testing
SINUS Multi-channel instrument + Extended Impedance tube + AFD software
The standard impedance tube may be extended to make a transmission tube (AFD 1000 plus AFD 1401 analysis software) from which may be determined the sound insulation values, the transmission coefficient, the complex impedance and the complex wave number (absorber parameter) by applying Song’s and Bolton’s transfer-matrix method. Using the obtained measurement results the insertion loss and the diffuse sound absorption coefficient (compared to measurements in a reverberation chamber according to DIN EN ISO 354) may be predicted directly.
AcoustiTube is based on a measurement technique in which a plane sound wave is emitted against a test sample in front of a reverberant termination within the impedance tube. The resulting sound pressure is measured by microphones in front and behind the sample. The two microphones are connected to a multi-channel instrument, such as the Soundbook, NoisePAD, Expander/Apollo/Apollo Lite Boxes plus laptop, all by SINUS Messtechnik GmbH. The AFD software is used to communicate with the acquisition device and to control the data acquisition measurements.
Sample holders
Depending on the application field different sample holders are available.
Sample holder I
Application field: Determination of sound transmision loss.
Samples: Cylindrical samples with a diameter of 15mm, 30mm, 40mm or 100mm.
Application: Mounting and soundproof sealing of prepared cylindrical samples of variable thickness on continuously adjustable and lockable sample holder.
Compression sample holder
The compression sample holder is an extension to the impedance and transmission tubes. It is almost continuously adjustable in length. Furthermore the compression sample holder allows defined compression of cylindrical samples or bulk sample material for determination of sound insulation. It also facilitates controlled installation of thin materials
Software
AFD 1401 Software Transmission
The AFD 1401 software, when installed in addition to the AFD1000.1 software, allows the determination of the sound insulation, the transmission coefficient, the complex impedance, the complex wave number and the transmission loss of open porous cylindrical specimens in the laboratory on the basis of the Two-Load Method. Selected measurements of different microphone distances and different system diameters in the frequency range may be averaged in accordance with DIN EN ISO 10534-2 using the AFD 1401 Viewer.
General technical specifications of AcoustiTube
15mm impedance tube
Inner diameter 15mm
Frequency range 150 … 10200Hz
30mm impedance tube
Inner diameter 30mm
Frequency range 150 … 6600Hz
40mm impedance tube
Inner diameter 40mm
Frequency range 100 … 4400Hz
100mm impedance tube
Inner diameter 100mm
Frequency range 50 … 2000Hz
Sample thickness
AFD 1000 260mm
AFD 1200 80mm
Compression sample holder 170mm