What is static electricity?
It is the electricity caused by stationary charges. When electric charges are present on the surface of a non-conducting body, where they are trapped and cannot escape, this body is said to have static electricity. The human body is subjected to an exchange of electric potential difference between the atmosphere and the earth, that is to say, it is constantly traversed by electric charges that it absorbs and then expels.
What are the consequences?
Creeps occur both ways: when transferring charges or receiving them, when touching or being touched. These extreme situations occur when the body has difficulty releasing the load gradually, either for a weather reason (lack of humidity) or clothing (insulating shoes and clothes). When he finally manages to release the load, he does so suddenly and the rampage ensues. If the contact is violent and brief, then the spark occurs.
How can it be avoided?
When the natural conditions, including humidity, are not conducive to the constitution of a conductive path that prevents the generation of static electricity, nor to dissipate the charges that are inevitably formed, we will have to resort to artificial conductive lines. The interconnection is made with the aim of reducing the potential differences between conducting objects to a minimum. One class of interconnection is the grounding of conductive objects. The humidity of the air works as a conductor that favors the exchange of tensions. If the environment is very dry, the body does not release its energy and is charged. This fact increases if acrylic clothes are worn or if insulating synthetic footwear is used, since shoes are the human body’s great grounding. All devices (photocopiers, printers, computers) generate static electricity, which is released by means of a ground outlet. If not, they are recharged, and then when the human body touches the device there is a potential difference between the two that becomes a surge.
In order to avoid this, we can resort to artificial conductive lines, such as the grounding of conductive objects. Use cotton clothes and shoes made of conductive materials: leather, hemp and esparto. It must be ensured that the environment is humid, using humidifiers, when the relative atmospheric humidity is low, or when the ventilation system dries the environment very much. The installation of homemade humidifiers can be advised, to raise the humidity of the environment and ensure that the electrical charges have better paths for their discharge. The maintenance of these humidifiers is very important. It is necessary to change the water very often to avoid the formation of fungi.
Bibliographic references
- Static electricity and electric current[enregistrament vídeo] . Barcelona: Ancora Audiovisual, Monday 1985.
- Smythe, William Ralph, Static and dynamic electricity . New York: McGraw-Hill, 1950.
- “Electricity. Low voltage”, in Safety at work: monographs . Fremap.
- López Beneyto, Felix; García-Asenjo Martín-Delgado, Fernando.”Electricity and our health”, in Safety at work: monographs . Fremap.
- Topic 3: Electrostatics.
- Risks due to static electricity, INSST, 2015.