Duct leakage testing — A duct leakage tester is a diagnostic tool designed to measure the airtightness of forced air heating, ventilating and air conditioning (HVAC) ductwork. A duct leakage tester consists of a calibrated fan for measuring an air flow rate and a… … Wikipedia
semiconductor device — ▪ electronics Introduction electronic circuit component made from a material that is neither a good conductor nor a good insulator (hence semiconductor). Such devices have found wide applications because of their compactness, reliability,… … Universalium
semiconductor — /sem ee keuhn duk teuhr, sem uy /, n. 1. a substance, as silicon or germanium, with electrical conductivity intermediate between that of an insulator and a conductor: a basic component of various kinds of electronic circuit element (semiconductor … Universalium
building construction — Techniques and industry involved in the assembly and erection of structures. Early humans built primarily for shelter, using simple methods. Building materials came from the land, and fabrication was dictated by the limits of the materials and… … Universalium
Vacuum — This article is about empty physical space or the absence of matter. For other uses, see Vacuum (disambiguation). Free space redirects here. For other uses, see Free space (disambiguation). Pump to demonstrate vacuum In everyday usage, vacuum is… … Wikipedia
dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or … Universalium
transistor — /tran zis teuhr/, n. 1. Electronics. a semiconductor device that amplifies, oscillates, or switches the flow of current between two terminals by varying the current or voltage between one of the terminals and a third: although much smaller in… … Universalium
electronics — /i lek tron iks, ee lek /, n. (used with a sing. v.) the science dealing with the development and application of devices and systems involving the flow of electrons in a vacuum, in gaseous media, and in semiconductors. [1905 10; see ELECTRONIC,… … Universalium
Vacuum pump — A vacuum pump is a device that removes gas molecules from a sealed volume in order to leave behind a partial vacuum. The vacuum pump was invented in 1650 by Otto von Guericke. Types Pumps can be broadly categorized according to three… … Wikipedia
Image noise — Noise clearly visible in an image from a digital camera Image noise is random (not present in the object imaged) variation of brightness or color information in images, and is usually an aspect of electronic noise. It can be produced by the… … Wikipedia