HP StorageWorks XP128 Installation Manual page 56

Over time, very fine whiskers of pure metal can form on electroplated zinc,
cadmium, or tin surfaces. If these whiskers are disturbed, they may break
off and become airborne, possibly causing failures or operational
interruptions. For over 50 years, the electronics industry has been aware of
the relatively rare but possible threat posed by metallic particulate
contamination. During recent years, a growing concern has developed in
computer rooms where these conductive contaminants are formed on the
bottom of some raised floor tiles.
Although this problem is relatively rare, it may be an issue in your
computer room. Since metallic contamination can cause permanent or
intermittent failures on your electronic equipment, Hewlett-Packard
strongly recommends that your site be evaluated for metallic particulate
contamination before the installation of electronic equipment.
Temperature and humidity specifications
When the disk array is operating, the recommended temperature range is
°
21° C to 24° C and recommended relative humidity range is (at 22 C)
between 40 to 55 percent. The following table lists the full range of
temperature, humidity, and vibration specifications for the HP Disk Array
XP128. The vibration and shock specifications apply to all three axes.
Caution
No condensation in or around the HP Disk Array XP128 should be
observed under any conditions.
56 HP StorageWorks Disk Array XP128: Site Preparation Guide