This chart shows the frequency spectrum of the noise emissions in the Motor Room of the L-1 Vertical Wind Tunnel located at Appalachian Amusement Center with the fan blades removed for inspection. This will help in the selection of sound absorbing material to treat the motor room, and the determination of how much motor room noise contributes to the external emissions of the machine. These measurements show that the drive cooling fans are as loud or louder than the motor below 630 Hz., and that the motor is about 10 to 20 db louder than the cooling fan from 630 to 4000 Hz. The zero readings are frequencies whose level was below the range of the measurements and so did not register.

Image shows sound meter located directly in front of the drive control panel.