Once a chamber has been constructed, its conformity cannot be judged by appearance alone; it must be accepted through a series of acoustic tests. The two most important metrics are the free field deviation and the noise floor. The free field deviation measures whether the room genuinely approaches an ideal free field: as the microphone is moved along a test path, the measured sound pressure level should decrease smoothly with distance according to the inverse square law, and the smaller the deviation, the more complete the absorption.
The noise floor reflects how quiet the room is in the absence of any source and is determined jointly by the isolation, the vibration control, and the ventilation system. The lower the noise floor, the fainter the signal the room can measure, and the wider its usable dynamic range becomes.
Acceptance is generally carried out in accordance with the applicable standard, such as ISO 3745, across the specified frequency range and in several directions, with a test report issued by a qualified third party. At handover, Anteck supports the client in completing these tests, ensuring that the actual performance of the laboratory conforms to the design specifications.