Seagate ST32000641AS ユーザーズマニュアル
12
Barracuda XT Series SATA Product Manual, Rev. C
2.8
Acoustics
Drive acoustics are measured as overall A-weighted acoustic sound power levels (no pure tones). 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.
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)
Table 3:
Drive A-weighted Sound Power Levels (SWL, BA)
Idle
[1]
Performance Seek
2000GB model
2.7 bels (typ)
2.9 bels (max)
2.9 bels (typ)
3.3 bels (max)
[1] During periods of drive idle, some offline activity may occur according to the S.M.A.R.T. specification, which may increase acoustic and power to
operational levels.
2.8.1
Test for Prominent Discrete Tones (PDTs)
Seagate follows the ECMA-74 standards for measurement and identification of PDTs. An exception to this process is the
use of the absolute threshold of hearing. Seagate uses this threshold curve (originated in ISO 389-7) to discern tone audi-
bility and to compensate for the inaudible components of sound prior to computation of tone ratios according to Annex D
of the ECMA-74 standards.
use of the absolute threshold of hearing. Seagate uses this threshold curve (originated in ISO 389-7) to discern tone audi-
bility and to compensate for the inaudible components of sound prior to computation of tone ratios according to Annex D
of the ECMA-74 standards.
2.9
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:
when subjected to the radio frequency (RF) environments defined in the following table:
Table 4:
Radio frequency environments
Test
Description
Performance level
Reference standard
Electrostatic
discharge
discharge
Contact, HCP, VCP: ± 4
kV; Air:
± 8 kV
B
EN61000-4-2: 95
Radiated RF
immunity
immunity
80 to 1,000MHz, 3 V/m,
80% AM with 1kHz sine
900MHz, 3 V/m, 50% pulse modulation @ 200Hz
A
EN61000-4-3: 96
ENV 50204: 95
Electrical fast
transient
transient
± 1 kV on AC mains, ± 0.5 kV on external I/O
B
EN61000-4-4: 95
Surge immunity
± 1 kV differential, ± 2 kV common, AC mains
B
EN61000-4-5: 95
Conducted RF
immunity
immunity
150kHz to 80MHz, 3 Vrms, 80% AM with 1kHz sine
A
EN61000-4-6: 97
Voltage dips,
interrupts
interrupts
0% open, 5 seconds
0% short, 5 seconds
40%, 0.10 seconds
70%, 0.01 seconds
C
C
C
B
EN61000-4-11: 94