HP Xb3000 HP xb3000 Notebook Expansion Base - Maintenance and Service Guide - Page 50

Removal and Replacement Preliminaries 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 tube 2,000 V 700 V 400 V 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 PCB 26,500 V 20,000 V 7,000 V Packing PCBs in foam-lined box 21,000 V 11,000 V ✎ A product can be degraded by as little as 700 V. 5,000 V 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 5,000 V 4-8 Maintenance and Service Guide