This noise indicator must comply with the contemporary technical specifications, for which purpose acoustic testing is performed. In order to improve the quality of such testing, Blauberg Ventilatoren has put into operation a new reverberation chamber.
The reverberation chamber is a fully isolated room with dimensions that allow testing of practically the entire range of ventilation products offered by the company – from household fans to industrial ventilation units. The maximum level of sound insulation of the chamber is achieved by utilization of soundproof walls made of six layers of plasterboard, two layers of rubber sheeting and acoustic mineral cotton, and soundproof doors designed to absorb noise up to 42 dB. The walls and the ceiling of the chamber do not have a direct contact with the building structures because its box is placed on special vibration damping supports made of polyurethane, which eliminates the possibility of sound vibrations entering the chamber from the outside.
In order to create multiple reflections of sound waves, the chamber box has an irregular shape, i.e. all its walls, floor and ceiling have different angles of inclination, which ensures that there are no parallel planes. This chamber configuration allows to minimize the reverberation time as a result of multiple reflections of sound from surfaces and at the same time ensures absorption of sound waves. The main measurement instruments are a multifunctional portable device that combines the functions of a sound level meter, a multi-channel vibration meter and a sound spectrum analyser, as well as several special microphones.
The new reverberation chamber is fully compliant with the requirements of international standards.