ST1.3 Series Product Manual, Rev. C 15
2.9 Acoustics
Drive acoustics are measured as overall A-weighted acoustic sound power levels (no pure tones). Discrete
tone penalties are added to the A-weighted sound power (LW) with the following formula only when determin-
ing compliance:
LWt(spec) == LW + 0.1Pt + 0.3 < 4.0 (Bels)
where
LW = A-weighted sound power level
pt == Value of discrete tone penalty [==dLt-6.0 (dBA)]
dLt = Tone-to-noise ratio taken in accordance with ISO 7779.
All measurements are consistent with ISO document 7779. Sound power measurements are taken under
essentially free-field conditions over a reflecting plane. For all tests, the drive is oriented with the cover facing
upward.
Note. For seek mode tests, the drive is placed in seek mode only. The number of seeks per second is defined
by the following equation:
(Number of seeks per second = 0.4 / (average latency + average access time)
2.10 Electromagnetic immunity
When properly installed in a representative host system, the drive operates without errors or degradation in
performance when subjected to the radio frequency (RF) environments defined in the following table:
Table 6: Drive level acoustics
Acoustic mode
Idle Operational
1.6 bels (typ)
1.7 bels (max)
1.9 bels (typ)
2.0 bels (max)
Table 7: Electromagnetic immunity
Test Description
Performance
level
Reference
standard
Radiated RF immunity 80 to 1,000 MHz, 3 V/m,
80% AM with 1 kHz sine
900 MHz, 3 V/m, 50% pulse modulation @ 200
Hz
AEN 61000-4-3: 96
ENV 50204: 95
Electrical fast transient ± 1 kV on AC mains, ± 0.5 kV on external I/O BEN 61000-4-4: 95
Surge immunity ± 1 kV differential, ± 2 kV common, AC mains BEN 61000-4-5: 95
Conducted RF immunity 150 kHz to 80 MHz, 3 Vrms, 80% AM with 1
kHz sine
AEN 61000-4-6: 97
Voltage dips, interrupts 0% open, 5 seconds
0% short, 5 seconds
40%, 0.10 seconds
70%, 0.01 seconds
C
C
C
B
EN 61000-4-11: 94