Sound Pressure (Reference); Sound Pressure Level - IBM DCAS-32160 - Ultrastar 2.1 GB Hard Drive Specifications

N 3 4 5
k 3.19 2.74 2.74
The calculated left hand side of the criterion equation above is rounded to the nearest 0.05 bel. The indi-
vidual terms may be rounded to the nearest 0.01 bel before calculation.

6.9.3 Sound Pressure (Reference)

6.9.3.1 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.

6.9.3.2 Sound Pressure Level

The hard disk drives meet the following sound pressure level.
Figure 47. Sound Pressure Level
Mode
Idle on Track
Random Operation
6 7 8
2.49 2.33 2.22 2.13
9 10 11 12
2.07 2.01 1.97
Mean
34 dBA
39 dBA
13 14 15
1.93 1.90 1.87
Max
38 dBA
42 dBA
53
Specification