Noise control measures for through shafts

MSAC / VSAC

The above is a diagram showing the case where power from outside the semi-anechoic chamber is connected to a rotating shaft inside the chamber (such as a dynamometer)

In this case, the wall of the semi-anechoic chamber needs to have ‘a hole’ for the shaft to pass through. Additionally, since the shaft will rotate, it is necessary to create a “condition where the hole does not make contact with the shaft.”

However, having a hole and a gap means that outside noise can enter the room (and vice versa).

To address this issue, our company developed a noise control unit for through shafts in 2004, with numerous successful installations. By using this unit, it is possible to design the system in such a way that it has no impact on the background noise levels inside the semi-anechoic chamber.