Radiation Noise; Conductive Noise; Magnetic Fields; Figure 19. Magnetic Flux Density Limits - Hitachi IC25N040ATCS04-0 - Travelstar 40GN 40GB UDMA/100 4200RPM 2MB 2.5" IDE Hard Drive Specifications

6.1.1.1 Corrosion test
The hard disk drive must be functional and show no signs of corrosion after being exposed to a
temperature humidity stress of 50°C/90%RH (relative humidity) for one week followed by a temperature
and humidity drop to 25°C/40%RH in 2 hours.

6.1.2 Radiation noise

The disk drive shall work without degradation of the soft error rate under the following magnetic flux
density limits at the enclosure surface.
Frequency (KHz)
0–60
61–100
101–200
201–400

Figure 19. Magnetic flux density limits

6.1.3 Conductive noise

The disk drive shall work without soft error degradation in the frequency range from DC to 20 Mhz injected
through any two of the mounting screw holes of the drive when an AC current of up to 45 mA (p-p) is
applied through a 50-ohm resistor connected to any two mounting screw holes.

6.1.4 Magnetic fields

The disk drive will withstand radiation and conductive noise within the limits shown below. The test
method is defined in the Noise Susceptibility Test Method specification, P/N 95F3944.
Hitachi Travelstar 60GH & 40GN hard disk drive specifications
Limits (Gauss RMS)
5
2.5
1
0.5
24