Hitachi IC25N080ATMR04-0 Specifications - Page 45
Acoustics
UPC - 000000114196
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The input level shall be applied to the normal disk drive subsystem mounting points used to secure the drive in a normal system. 6.5.4 Nonoperating shock The drive withstands the following half-sine shock pulse without any data loss or permanent damage. Table 22: Nonoperating shock Duration of 1 ms Duration of 11 ms 7840 m/sec2 (800 G) 1176 m/sec2 (120 G) The shocks are applied for each direction of the drive for three mutually perpendicular axes, one axis at a time. Input levels are measured on a base plate where the drive is attached with four screws 6.6 Acoustics 6.6.1 Sound power levels The criteria of A-weighted sound power level are described below. Measurements are to be taken in accordance with ISO 7779. The mean of the sample of 40 drives is to be less than the typical value. Each drive is to be less than the maximum value. The drives are to meet this requirement in both board down orientations. Table 23: Weighted sound power 40GB, 30GB, 20GB models 80GB, 60GB models Idle Operating Idle Operating A-weighted sound power Typical (Bels) 2.0 2.4 2.3 2.7 Maximum (Bels) 2.3 2.6 2.6 2.9 The background power levels of the acoustic test chamber for each octave band are to be recorded. Sound power tests are to be conducted with the drive supported by spacers so that the lower surface of the drive be located 25±3 mm above from the chamber floor. No sound absorbing material shall be used. The acoustical characteristics of the disk drive are measured under the following conditions: Mode definitions • Idle mode: Power on, disks spinning, track following, unit ready to receive and respond to control line commands. • Operating mode: Continuous random cylinder selection and seek operation of the actuator with a dwell time at each cylinder. The seek rate for the drive is calculated with the following formula: Ns= 0.4/(Tt + T1) where: Ns = average seek rate in seeks/s Travelstar 80GN Hard Disk Drive Specification 35