An electrostatic discharge (ESD) is a transfer of energy between two differently charged objects. Most people have experienced ESD in the form of static shock. In addition to being startling, ESD can cause severe damage to electronics, and for this reason many manufacturers install safeguards to protect against ESD. There are some steps consumers should take to avoid ESD, especially around motor vehicles.
ESD occurs when two objects with a different number of electrons, which causes a difference in energy potentials, encounter each other. A classic example occurs when someone walks across a floor, picks up electrons and becomes charged, and then touches an object in the room, causing the extra electrons to discharge, resulting in a shock. When two objects in close proximity to each other build up a large electrostatic field, this can also result in an ESD. Moving humans can build up a surprisingly high static charge.
Because it is an electrical phenomenon, ESD can damage electrical components. ESD is accompanied by intense heat, although humans don't usually feel it. This heat, however, can cause severe damage to small electrical components when an ESD is focused on them. The electrical pulse which forms the core of an ESD also acts like a power surge on electrical devices, and can short out or permanently damage the system.
This is especially a concern in the computer industry, where many components are shipped in anti-static bags to avoid damage, and technicians are encouraged to discharge static electricity before performing work. In addition, many factories used specialized flooring which is supposed to dissipate static electricity, rather than allowing workers to collect it.
The most simple way of preventing ESD whether at home, on the factory floor, or in a vehicle, is to use grounding. Many companies, for example, sell grounding straps for cars which will prevent a static buildup. In addition, before fueling a vehicle motorists should always touch a metal portion of the car away from the gas cap, to ensure that any static charge built up from seat cushions or flooring is dissipated before contact with flammable fuels.
A universal ground in a factory will likewise divert a charge before it can build up and cause ESD. Workers can wear grounding straps and shoes with grounding capability while walking on a grounded floor and using grounded workbenches. In addition, factories should control their humidity levels, because ESD is far more likely to occur in areas of low humidity. The use of a solid ground will allow the electrostatic energy to discharge harmlessly and in a controlled fashion, preventing damage.