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ESD Anti Static - Definitions
ESD:
ESD = Electro Static Discharge.
Official pictogram for electro static discharge:

(Electro-) Static Dissipative:
Defines the capacity of a material to discharge electric charges through grounding. In electrostatic dissipative materials, electrons are either dispersed onto or through the material; however, the flow of electrons is contained by surface- or volume resistivity.
Electrically Conductive:
Defines the capacity of a material to conduct electricity. When a conductive material is charged, electrons are distributed equally. When two conductive materials come into contact with each other, the exchange of electrons may be so rapid as to cause a short circuit.
Surface Resisitivity:
Measuring unit for electrical resistivity on the surface of an object or material, i.e. in reverse conclusion, the degree of electric conductivity. Unit of measurement: Ohm (Ω).
Surface Potential:
Simply put, the electro static surface potential indicates the extent of the electric charge of an object or material.
Generally, the surface potential is measured in Volt. As soon as an object
or material is subjected to an electric charge potential, a discharge may occur subsequently (further factors which may cause discharge are: the size of the contact area, the speed of separation, relative humidity, electric resistivity).
Humans are only able to perceive electric charges of more than 3,000 volt.
The electric charge potential, i.e. the discharge capacity respectively, highly depends on the relative humidity. The lower the relative humidity, the higher the probability of an electrostatic charge.
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ESD-Cause |
Electric Surface Potential at 10-20% Humidity |
Electric Surface Potential at 60-95% Humidity |
Walking across a carpeted floor |
35,000 Volt |
1,500 Volt |
Walking across a vinyl floor |
12,000 Volt |
3,000 Volt |
Walking across a linoleum floor |
12,000 Volt |
250 Volt |
Working at a workbench |
6,000 Volt |
100 Volt |
Paper in plastic covers |
7,000 Volt |
600 Volt |
Plastic bags |
20,000 Volt |
1,200 Volt |
Padded chair |
18,000 Volt |
1,500 Volt |
Source: Data according to US Dept. of Defense Hb 263.1980
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