Electrostatic Voltage Levels And Protective Materials - HP ProSignia 120 Maintenance And Service Manual

Other grounding equipment recommended for use in preventing electrostatic damage
include:
Antistatic tape
Antistatic smocks, aprons, or sleeve protectors
Conductive bins and other assembly or soldering aids
Non-conductive foam
Conductive tabletop workstations with ground cord of one-megohm resistance
Static-dissipative table or floor mats with hard tie to ground
Field service kits
Static awareness labels
Material-handling packages
Non-conductive plastic bags, tubes, or boxes
Metal tote boxes
4.4.4 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
Removing DIPS from Styrofoam
Removing bubble pack from PCB
Packing PCBs in foam-lined box
NOTE: 700 volts can degrade a product.
Table 4-1
Typical Electrostatic Voltage Levels
Relative Humidity
10%
35,000 V
12,000 V
6,000 V
2,000 V
11,500 V
14,500 V
26,500 V
21,000 V
40% 55%
15,000 V 7,500 V
5,000 V 3,000 V
800 V 400 V
700 V 400 V
4,000 V 2,000 V
5,000 V 3,500 V
20,000 V 7,000 V
11,000 V 5,000 V
Removal and Replacement Preliminaries 4-5