What Is an Acoustic Anechoic Chamber?
Anechoic chamber is a room designed to block out external sound waves (soundproofing) and prevent sound from reflecting within the room (sound absorption). It is used for measuring noise from automotive parts, household appliances, and other sources with noise meters and analyzers.
Examples of standards related to the Acoustic Anechoic chamber
– ISO3741: Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Precision methods for reverberation test rooms
– ISO3744: Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering methods for an essentially free field over a reflecting plane
– ISO3745: Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Precision methods for anechoic rooms and hemi-anechoic rooms
– ISO362-1, 2, 3: Acoustics – Engineering method for measurement of noise emitted by accelerating road vehicles…
– ISO13325: Tyres – Coast-by methods for measurement of tyre-to-road sound emission
– ISO26101-1: Acoustics – Test methods for the qualification of the acoustic environment
– ISO11201: Acoustics – Noise emitted by machinery and equipment – Determination of emission sound pressure levels at a workstation and at other specified positions in an essentially free field over a reflecting plane with negligible environmental corrections
– etc…
Types of Anechoic chambers
[Anechoic chambers used for each purpose]
1 Anechoic chambers for acoustical measurements
2 Anechoic chambers for electromagnetic compatibility (EMC), electromagnetic interference (EMI) and RF testing
[Differences in each shape and DUT (device under test)]
1 Fully anechoic chamber: sound absorption layer on six faces (floor, walls and ceiling) often used to measure consumer electronics and compact driving components.
2 Semi-anechoic chamber: sound absorption layer on 5 faces (walls and ceiling) often used to measure DUT to be placed on the ground such as automobile
Depending on the measurement purpose, anechoic chambers may be referred as followings:
– VSAC: Vehicle Semi-Anechoic Chambers
– EAAC: Electroacoustic Anechoic Chambers
– SPAC: Sound Power Anechoic Chambers