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2.10Acoustics

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.

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 Fluid Dynamic Bearing (FDB) motor acoustics

 

Idle*

Performance Seek

 

 

 

3 Disks

2.5 bels (typical)

2.5 bels (typical)

(3TB)

2.6 bels (max)

2.6 bels (max)

 

 

 

2 Disk

2.4 bels (typical)

2.4 bels (typical)

(2TB)

2.5 bels (max)

2.5 bels (max)

 

 

 

1 Disk

2.2 bels (typical)

2.2 bels (typical)

(1TB)

2.3 bels (max)

2.3 bels (max)

 

 

 

*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.

2.11Test 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 audibility and to compensate for the inaudible components of sound prior to computation of tone ratios according to Annex D of the ECMA- 74 standards.

2.12Electromagnetic immunity

When properly installed in a representative host system, the drive operates without errors or degradation in performance when subjected to the radio frequeny (RF) environments defined in Table 4.

Table 4 Radio frequency environments

Test

Description

Performance

Reference

level

standard

 

 

 

 

 

 

Electrostatic discharge

Contact, HCP, VCP: ± 4 kV; Air: ± 8 kV

B

EN61000-4-2: 95

 

 

 

 

Radiated RF immunity

80MHz to 1,000MHz, 3 V/m,

A

EN61000-4-3: 96

 

80% AM with 1kHz sine

 

ENV50204: 95

 

900MHz, 3 V/m, 50% pulse modulation @ 200Hz

 

 

 

 

 

 

Electrical fast 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,

B

EN61000-4-5: 95

 

AC mains

 

 

 

 

 

 

Conducted RF immunity

150kHz to 80MHz, 3 Vrms, 80% AM with 1kHz

A

EN61000-4-6: 97

 

sine

 

 

 

 

 

 

Voltage dips, interrupts

0% open, 5 seconds

C

EN61000-4-11: 94

 

0% short, 5 seconds

C

 

 

40%, 0.10 seconds

C

 

 

70%, 0.01 seconds

B

 

 

 

 

 

Constellation CS Serial ATA Product Manual, Rev. C

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Seagate ST3000NC000, ST1000NC001, ST1000NC000 Acoustics, Test for Prominent Discrete Tones PDTs, Electromagnetic immunity