Sound Pressure (Reference) - IBM DDRS-39130 - Ultrastar 9.1 GB Hard Drive Specifications

6.10.2 Sound Pressure (Reference)

6.10.2.1 Unit Sound Pressure Level Measurment
The hard disk drives are measured in a semi-anechoic chamber, with background noise = < 25 dBA. Sur-
faces to be measured are top cover side and card side. Microphone is set one meter above the drive surface.
Random operation mode is simulated with 40% seek and 60% idle in time.
6.10.2.2 Sound Pressure Level
The hard disk drives meet the following sound pressure level.
Figure 52. Sound Pressure Level
Mode
Idle on Track
Random Operation
Mean
34 dBA
39 dBA
Max
38 dBA
42 dBA
57
Specification