Compaq V300 Typical Electrostatic Voltage Levels, Static-Shielding Materials, Event 10% 40% 55%

Table 4-1 shows how humidity affects the electrostatic voltage levels generated by different activities.

Table 4-1

Typical Electrostatic Voltage Levels

			Relative Humidity
Event	10%		40%		55%
Walking across carpet	35,000	V	15,000	V	7,500	V
Walking across vinyl floor	12,000	V	5,000	V	3,000	V
Motions of bench worker	6,000	V	800	V	400	V
Removing DIPS from plastic	2,000	V	700	V	400	V
tube
Removing DIPS from vinyl tray	11,500	V	4,000	V	2,000	V
Removing DIPS from Styrofoam	14,500	V	5,000	V	3,500	V
Removing bubble pack from	26,500	V	20,000	V	7,000	V
PCB
Packing PCBs in foam-lined	21,000	V	11,000	V	5,000	V
box

NOTE: A product can be degraded by as little as 700 volts.

Table 4-2 lists the shielding protection provided by antistatic bags and floor mats.

Table 4-2

Static-Shielding Materials

Material	Use	Voltage Protection Level
Antistatic plastic	Bags	1,500 V
Carbon-loaded plastic	Floor mats	7,500 V
Metallized laminate	Floor mats	15,000 V

4-6Removal and Replacement Preliminaries