Hitachi IC25N040ATCS04-0 Specifications - Page 50

Acoustics

Get Hitachi IC25N040ATCS04-0 - Travelstar 40GN 40GB UDMA/100 4200RPM 2MB 2.5inch IDE Hard Drive PDF manuals and user guides
UPC - 683728198664
View all Hitachi IC25N040ATCS04-0 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 50 highlights

6.7 Acoustics 6.7.1 Sound power level 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. A-weighted Sound Power 48 GB model 30 GB and 20 GB models All other models Typical (Bels) Idle Operating 2.5 3.5 2.4 3.1 2.1 2.7 Maximum (Bels) Idle Operating 2.7 3.8 2.6 3.3 2.4 2.9 Figure 33. Weighted sound power 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 can be calculated as shown below. Ns = 0.4/(Tt + T1) where: Ns = average seek rate in seeks/s Tt = published seek time from one random track to another without including rotational latency T1= equivalent time in seconds for the drive to rotate by half a revolution Hitachi Travelstar 60GH & 40GN hard disk drive specifications 37

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
6.7 Acoustics
6.7.1 Sound power level
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.
2.9
2.4
2.7
2.1
All other models
3.3
2.6
3.1
2.4
30 GB and 20 GB models
3.8
2.7
3.5
2.5
48 GB model
Operating
Idle
Operating
Idle
Maximum (Bels)
Typical (Bels)
A-weighted Sound Power
Figure 33. Weighted sound power
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 can be calculated as shown below.
Ns = 0.4/(Tt + T1)
where:
Ns = average seek rate in seeks/s
Tt = published seek time from one random track to another without including rotational
latency
T1= equivalent time in seconds for the drive to rotate by half a revolution
Hitachi Travelstar 60GH & 40GN hard disk drive specifications
37