Description
AED 800 - AcoustiAdrienne Sound Absorption Measurement Device
Overview
The AED 800 - AcoustiAdrienne sound absorption measurement device is used to non-destructively measure the sound absorption coefficient and sound reflection factor of test specimens in situ based on the Adrienne method described in DIN ISO 13472-1 and DIN EN 1793-5. The rated sound absorption coefficient of the material can be directly determined from the measurement results according to DIN EN ISO 11654.
Principle of sound absorption measurement device
To determine the sound absorption properties in situ, two measurements must be performed, one measurement with the test specimen and one measurement without the test specimen (free field). From the first measurement with the test specimen, an impulse response is calculated that includes a direct component, a reflected component of the test material, and additional reflected components caused by surrounding obstacles. The latter can be excluded by applying a specific time window. From the second measurement without the test specimen (free field), an impulse response is calculated that includes only a direct component. Finally, the sound absorption coefficient and the sound reflection factor of the test specimen to be characterized can be determined by subtracting the two calculated impulse responses.
Application areas
The measurement method was originally developed for the non-destructive evaluation of the acoustic properties of road surfaces. For some time now, the measurement method has also been used to determine the acoustic properties of noise barriers. The AED 800 - AcoustiAdrienne measurement system therefore allows the following:
Measurement of the sound absorption coefficient and the sound reflection factor of road surfaces according to DIN ISO 13472-1 (sound absorption coefficient > 0.15) Measurement of the sound absorption coefficient and the sound reflection factor of noise barriers and screens according to DIN CEN/TS 1793-5 and DIN EN 1793-5 Determination of the Miller index of noise barriers as well as the Miller index difference of screen supports (influence of screen crowns on sound diffraction) according to DIN CEN/TS 1793-4 and DIN EN 1793-4 Determination of the sound insulation of noise barriers according to DIN CEN/TS 1793-5 and DIN EN 1793-6
Based on the basic measurement method, the following can also be evaluated:
The sound absorption coefficient and the sound reflection factor of plate-shaped test specimens of open-cell material
In contrast to the use of the impedance tube AED 1000/1200 - AcoustiTube®, the sound absorption coefficient can be determined not only for vertical sound incidence but also for statistical sound incidence. The application of a special model to take into account the edge diffraction effect enables direct comparison of the results with measurement results obtained in the reverberation room according to DIN EN ISO 354.
Software
The AED 800 measurement system is supported by the analysis software AED 801.