Thin-film thickness monitors, deposition rate controllers, and so on, are a family of instruments used in high and ultra-high vacuum systems. They can measure the thickness of a thin film, not only after it has been made, but while it is still being deposited, and some can control either the final thickness of the film, the rate at which it is deposited, or both.
An ammeter is a measuring instrument used to measure the electric current in a circuit. Electric currents are measured in amperes (A), hence the name. Smaller values of current can be measured using a milliameter or a microammeter. Early ammeters were laboratory instruments only which relied on the Earth's magnetic field for operation. By the late 19th century, improved instruments were designed which could be mounted in any position and allowed accurate measurements in electric power systems,
A katharometer is a thermal conductivity device for determining one gas in a binary or pseudo-binary mixture. The thermal conductivity of a gas is inversely related to its molecular weight. Hydrogen has approximately six times the conductivity of nitrogen for example.
Many techniques have been developed for the measurement of pressure and vacuum. Instruments used to measure pressure are called pressure gauges or vacuum gauges. A manometer could also be referring to a pressure measuring instrument, usually limited to measuring pressures near to atmospheric. The term manometer is often used to refer specifically to liquid column hydrostatic instruments.
In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Established standard objects and events are used as units, and the process of measurement gives a number relating the item under study and the referenced unit of measurement. Measuring instruments, and formal test methods which define the instrument's use, are the means by which these relations of numbers are obtained.
Radar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1940 by the U.S. Navy as an acronym for RAdio Detection And Ranging. The term has since entered the English language as a standard word, radar, losing the capitalization.
A spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization state.
A voltmeter is an instrument used for measuring the electrical potential difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of an analog to digital converter. Voltmeters are made in a wide range of styles. Instruments permanently mounted in a panel are used to monitor generators or other fixed apparatus.
A Wheatstone bridge is a measuring instrument invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843 . It is used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. Its operation is similar to the original potentiometer.
An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical hand-made mechanical instruments to high-precision electronic devices. Modern electrometers based on vacuum tube or solid state technology can be used to make voltage and charge measurements with very low leakage currents, down to 1 femtoampere.
The domino theory was a foreign policy theory during the 1950s to 1980s, promoted at times by the government of the United States, that speculated that if one land in a region came under the influence of communism, then the surrounding countries would follow in a domino effect.
The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List), founded in 1948, is the world's most comprehensive inventory of the global conservation status of plant and animal species. The International Union for the Conservation of Nature and Natural Resources (IUCN) is the world's main authority on the conservation status of species.
The Democratic Revolutionary Party is a Panamanian political party. It was founded in 1979 by the General Omar Torrijos, and is generally described as a party of the centre-left of the political spectrum.
Anonymous (used as a mass noun) is a label and Internet meme adopted within Internet culture to represent the actions of many online community users acting anonymously, usually toward a loosely agreed-upon goal. It is generally considered to be a blanket term for members of certain Internet subcultures. Actions attributed to Anonymous are undertaken by unidentified individuals who apply the Anonymous label to themselves.