Alava Ingenieros installs an anechoic chamber for the Spanish Metrology Center

The anechoic chamber made by Alava Ingenieros for the Spanish Metrology Centre (EMF), Allow for accurate acoustic measurements and fieldwork.

Alava Ingenieros The project to install an anechoic chamber for the Spanish Metrology Centre (EMF), an autonomous body attached to the General Secretariat of Industry.

Located in the Acoustics Laboratory of the CEM, The anechoic chamber has the peculiarity that it is electromagnetically isolated, which facilitates work at very high frequencies (even up to 60 khz) and has a retrotractable floor, which allows for significant improvements in the free field measurements.

As Nieves Medina points out, of the Spanish Metrology Centre, "Inside this chamber, every sound wave produced is absorbed by the walls of the chamber, so that there are no reflections. This effect is mainly produced by the fact that the interior walls are covered with wedges made of special absorbent material whose shape has been specially designed for this purpose".

The anechoic chamber has an internal volume of about 35 m3 and "also functions as a Faraday cage, preventing any external electromagnetic field from penetrating inside. It is the quietest place in Spain", Medina points out.

In general, a person can hear between 20 Hz and 20 khz, While this camera performs optimally in most of this range, since 160 Hz to 20 khz. "To optimally cover the lower range," says this expert, "a flat wave tube has been installed that provides anechoic conditions, which is a square section conduit of about 9 m. long with an absorbent wedge specially designed for this purpose".

The purpose of this camera is to make acoustic measurements from fully known sound waves, since inside it there are no reflex waves or unwanted interference that can disturb these waves.

The camera has adequate lighting for this purpose so that it does not affect the acoustic field or cause temperature gradients, located with millimeter accuracy.