Acoustics; Electromagnetic Immunity - Seagate ST9500421AS Product Manual

2.11

Acoustics

Drive emission of sound is measured consistent with the ECMA-74 and its' referenced standards. Testing is
conducted at room temperature (approximately 25
sound power levels for steady state, idle, and active seek modes of operation.
Idle* Performance seek
2.3 bels (typ) 2.5 bels (typ)
2.5 bels (max) 2.7 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.
2.12

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:
14
C). Emission levels are reported as the total A-weighted
°
Momentus 7200 FDE.2 SATA Product Manual, Rev. A