To prepare coffee, a filter is usually used.
The first step we are going to take before entering into the meaning of the term filter is to know its etymological origin. In this case, we can point out that it is a word that derives from Latin, specifically from filtrum , which, in turn, comes from the Germanic filt .
A filter is a device that retains certain elements and lets others pass through . The concept usually refers to the porous material that allows the transit of a liquid but blocks the particles that the fluid carries in suspension.
For example: “I need to buy filters so I can prepare more coffee,” “In my house we have a water filter to drink directly from the tap,” “The mechanic recommended I replace the oil filter in my car.”
Different types of filters
In different contexts, a filtration funnel is used which, equipped with a paper , makes it possible to eliminate impurities or solids from a solution: while these particles remain in the filter, the liquid passes into another container or container. Filter paper or filter paper is used, for example, in electric coffee makers .
An air filter , meanwhile, is used to eliminate pollen , dust and other solid particles that can be found in the environment. These filters are common in engine and building ventilation systems.
Cigarettes, for their part, have a filter to ensure that certain toxic particles present in the smoke are not inhaled by the smoker. Tobacco filters are usually made from cellulose.
Cigarettes include a filter.
Its use in the pool and in electronics
Likewise, we cannot forget the existence of pool filters either. These are devices that are placed in the treatment plant of the aforementioned pool and whose main function is to clean and purify the water in that pool. To do this, it eliminates any impurities that may exist and thanks to this work it allows the water to be in optimal conditions so that people can take a bath in it.
Currently, there are numerous types of pool filters, although among the most significant are the sand filter, which is the most used and most popular; the diatom one or the cartridge one.
There are also electronic filters or electrical filters , capable of discriminating certain frequencies of electrical signals that pass through them. There are analog filters and digital filters .
Symbolic uses of the term filter
In the same way, it is used with another meaning within the more colloquial sphere. Specifically, it is used to refer to a person who says things just as they come to mind, without thinking and without taking into account the consequences that their words may bring. Thus, an example would be the following: “Manuel has no filter. He told Pepe clearly and directly that his wife was being unfaithful to him and also with whom.”
Filter, finally, is the name given to the selection system or process that consists of eliminating candidates or applicants: “Of the thousand students who took the university entrance exam, eight hundred failed to pass the filter.”