Seagate ST9120821SB, ST98823SB manual Acoustics, Electromagnetic immunity, Drive level acoustics

2.11Acoustics

Drive acoustics are measured as overall A-weighted acoustic sound power levels (no pure tones). All mea- surements 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.

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 4: Drive level acoustics

Idle*	Performance Seek
2.4 bels (typ)	2.9 bels (typ)
2.6 bels (max)	3.1 bels (max)

Note. *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.

2.12Electromagnetic 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 5:	Radio frequency environments
Test		Description	Performance level	Reference standard
Electrostatic discharge		Contact, HCP, VCP: ± 4 kV; Air: ± 8 kV	B	EN 61000-4-2: 95
Radiated RF immunity		80 to 1,000 MHz, 3 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/	B	EN 61000-4-4: 95
		O
Surge immunity		± 1 kV differential, ± 2 kV common, AC	B	EN 61000-4-5: 95
		mains
Conducted RF immunity		150 kHz to 80 MHz, 3 Vrms, 80% AM with	A	EN 61000-4-6: 97
		1 kHz sine
Voltage dips, interrupts		0% open, 5 seconds	C	EN 61000-4-11: 94
		0% short, 5 seconds	C
		40%, 0.10 seconds	C
		70%, 0.01 seconds	B

12 Momentus 5400.2 SATA Blade Server Product Manual, Rev. B