Leakage
From Wikipedia, the free encyclopedia
Leakage describes an unwanted loss, or leak, of something which escapes from its proper location:
- In everyday usage and chemistry, leakage is the gradual escape of matter through a leak, usually liquid or powder from an imperfectly sealed container.
- In electronics, leakage may mean the gradual loss of energy from a charged capacitor, or unwanted transfer of energy from one circuit to another.
- In the retail trade, leakage or shrinkage means a loss of stock.
- Semiconductor leakage is unwanted quantum tunneling through an insulating region.
- In sound recording, leakage (also called spillage) occurs when audio intended for one track is picked up inadvertently by another track's microphone.
- In medicine, anal leakage is a condition of faecal incontinence.
- In manufacturing, "spillage" is the loss of production output due to production of a series of defective or unacceptable products which must be rejected.
- In tourism, leakage refers to the loss of tourist revenue from a country. (See leakage effect).
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[edit] Chemistry
In chemistry, leakage is a process in which material is lost, intentionally or accidentally, gradually through the holes or defects of their containers. Often, leakage can be disastrous if the leaked material is harmful or corrosive.
A zinc-carbon battery is an example of an easy-leaking system. The electrolytes inside the cell sometimes leak out of the cell shell, and cause damage to an electronic appliance.
[edit] Electronics
In electronics, leakage is an undesired imperfection of some dielectric materials used in capacitors, also known as dielectric leakage. It is a result of the dielectric material not being a perfect insulator and therefore allowing a leakage current to flow, slowly discharging the capacitor.
We also speak of (unwanted) leakage of energy from one circuit to another. For example, magnetic lines of flux will not be entirely confined within the core of a power transformer; another circuit may couple to the transformer and receive some leaked energy at the frequency of the electric mains, which will cause audible hum in an audio application.
[edit] Retail
Retail leakage occurs when members of a community spend money outside that community or when money spent inside that community is transferred outside the community. For example, crossing a border to buy goods forgoes the same purchase that could have been made inside the community.
Many chain stores have high leakages rates due to the transferring of sales revenue to a corporate headquarters. Also, in retail, leakage can mean the loss of stock without payment, typically due to theft by employees or shoplifters.
[edit] Semiconductors
In semiconductor devices, leakage is a quantum phenomenon
[edit] Sound recording
Multitrack recording is at its optimum when there is sufficient isolation between individual tracks, to allow for freedom in remixing each track to a desired sound level. Reasonable isolation can be achieved (even in a live recording) by careful microphone placement, or by the separation of sound sources. Sound leakage can limit or even ruin the remixing and overdubbing potentials for a multitrack recording, when one sound interferes with another sound on a track.
[edit] Manufacturing
Spillage is an often costly event which occurs in manufacturing when a process degradation or failure occurs that is not immediately detected and corrected, and in which defective or reject product therefore continues to be produced for some extended period of time. Spillage results in costs due to lost production volume, excessive scrap, delayed delivery of product, and wastage of human and capital equipment resources. Minimization of the occurrence and duration of manufacturing spillage requires that closed-loop control and associated process monitoring and metrology functions be integrated into critical steps of the overall manufacturing process. The extent to which process control is complete and metrology is high-definition so as to be comprehensive determines the extent to which spillages will be prevented.
