Seagate ST9200827AS manual Acoustic emission, Electromagnetic immunity, Drive level acoustics

2.11Acoustic emission

Drive emission of sound is measured consistent with the ECMA-74 and its’ referenced standards. Testing is conducted at room temperature (approximately 25C). Emissino levels are reported as the total A-weighted sound power levels for, steady state, idle and active (seek) modes of operations.

Table 5:	Drive level acoustics
Models			Idle*	Performance seek
2 discs		ST9250827AS	2.4 bels (typ)	2.6 bels (typ)
		ST9200827AS	2.6 bels (max)	2.8 bels (max)
		ST9160827AS
1 disc		ST9120817AS	2.2 bels (typ)	2.9 bels (typ)
			2.4 bels (max)	3.1 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.

Test for Prominent Discrete Tones (PDTs)

Seagate follows the ECMA-74 standards for measurement and identification of PDTs. An exception to this pro- cess is the use of the absolute threshold of hearing. Seagate uses the lower limit for the threshold curve* 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.

* Defined as the median curve given by ISO 389-7 (Tf curve) minus 10dB at all frequencies.

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 frequency (RF) environments defined in the following table:

Table 6:	Radio frequency environments
			Performance	Reference
Test		Description	level	standard
Electrostatic discharge		Contact, HCP, VCP: ± 4 kV; Air: ± 8 kV	B	EN 61000-4-2: 95
Radiated RF immunity		80 to 2,000 MHz, 10 V/m,	A	EN 61000-4-3: 96
		80% AM with 1 kHz sine		ENV 50204: 95
		900 MHz, 3 V/m, 50% pulse modulation @ 200 Hz
Electrical fast transient		± 1 kV on AC mains, ± 0.5 kV on external I/O	B	EN 61000-4-4: 95
Surge immunity		± 1 kV differential, ± 2 kV common, AC mains	B	EN 61000-4-5: 95
Conducted RF immunity		150 kHz to 80 MHz, 3 Vrms, 80% AM with 1 kHz	A	EN 61000-4-6: 97
		sine
Power Frequency H-field		1 A/m, 50Hz/60Hz, 3 axes	A	EN 61000-4-8: 97
immunity
Voltage dips, interrupts		30% Reduction for 25 cycles	C	EN 61000-4-11: 94
		>95% Reduction for 250 cycles	C
		>95%, 0.5 cycles	B

Momentus 5400.4 SATA Product Manual, Rev. A 13