HP Compaq nx9500 Series Maintenance And Service Manual page 94

Removal and Replacement Preliminaries
Other grounding equipment recommended for use in preventing
electrostatic damage includes:
■
Antistatic tape
■
Antistatic smocks, aprons, and sleeve protectors
■
Conductive bins and other assembly or soldering aids
■
Nonconductive foam
■
Conductive tabletop workstations with ground cords of
one megohm resistance
■
Static-dissipative tables or floor mats with hard ties to
the ground
■
Field service kits
■
Static awareness labels
■
Material-handling packages
■
Nonconductive plastic bags, tubes, or boxes
■
Metal tote boxes
■
Electrostatic voltage levels and protective materials
Table 4-1 shows how humidity affects the electrostatic voltage
levels generated by different activities.
Event
Walking across carpet
Walking across vinyl floor
Motions of bench worker
Removing DIPS from plastic tube
Removing DIPS from vinyl tray
✎
A product can be degraded by as little as 700 V.
4–6
Typical Electrostatic Voltage Levels
Table 4-1
10%
35,000 V
12,000 V
6,000 V
2,000 V
11,500 V
Maintenance and Service Guide
Relative Humidity
40%
15,000 V
5,000 V
800 V
700 V
4,000 V
55%
7,500 V
3,000 V
400 V
400 V
2,000 V