Anechoic Chambers Test Room

What is an Anechoic Chamber?

Eishin Engineering and Supplies Co.,Ltd Offers both Anechoic chambers.

• Anechoic chambers (or rooms) are fully lined with anechoic wedges, including the floor, to create a specific, controlled test environment for professional acoustical testing.

An anechoic chamber can be considered similar to a precision acoustical measurement instrument, providing a free-field environment without noise interference or sound reflection. In an ideal free-field environment, the inverse square law would function perfectly. This means that the sound level from a spherically radiating sound source decreases by 6dB for each doubling of distance from the source. For a free field to exist with perfect inverse square law characteristics, room boundaries must have a sound absorption coefficient of unity at all angles of incidence. In practice this is usually not quite perfect and deviations from the inverse square law are to be expected.

Our Solutions

.

The fully anechoic chamber from Eishin Engineering and Supplies Co.,Ltd is designed for the research physicist or engineer who must make precise sound measurements in a free-field acoustic environment. These rooms provide high sound transmission loss (TL) characteristics and have a completely anechoic wedge-lined interior to meet these requirements.

Construction of Anechoic Rooms

For anechoic rooms to function well, a number of acoustic, mechanical, electrical and aerodynamic considerations apply. These will include some, or all, of the following:

• Anechoic treatment selection
• Cut-off frequency
• Internal acoustic ambient
• noise level Noise reduction
• Vibration isolation
• Silenced ventilation systems

• Acoustic doors operation and sizing
• Interior floors suspended cable floors
• Lighting and electrical systems
• Overall structural design considerations
• RF shielding requirements

Anechoic Wedges

One practical well proven method to achieve a free-field is to shape sound absorbing material into wedge configurations for mounting on to the interior surfaces. The wedge shaped geometry ensures a gradual change in the acoustic impedance of the transmission media, ensuring that sound waves are absorbed by the material, rather than reflected at an interface. The effectiveness of the absorption depends on the geometry and materials used. The lowest frequency at which the absorption is effective (cut-off frequency) is inversely proportional to the depth of the wedge. impedance tube is used for critical adjustment of wedge dimensions before finalising each design. Due to variations in material characteristics, statistical quality control measures are employed during wedge production to ensure specified acoustic performance.

Anechoic Chambers Gallery