kelvin


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Related to kelvin: Kelvin scale, Lord Kelvin

SI units

 
the units of measurement generally accepted for all scientific and technical uses; together they make up the International System of Units. (See also metric system.) The abbreviation SI, from the French Système International d'Unités, is used in all languages. There are seven base SI units, defined by specified physical measurements, and two supplementary units. Units are derived for any other physical quantities by multiplication and division of the base and supplementary units. The derived units with special names are shown in the accompanying table.



SI is a coherent system. This means that units are always combined without conversion factors. The derived unit of velocity is the meter per second (m/s); the derived unit of volume is the cubic meter (m3). If you know that pressure is force per unit area, then you know that the SI unit of pressure (the pascal) is the unit of force divided by the unit of area and is therefore equal to 1 newton per square meter.

The metric prefixes can be attached to any unit in order to make a unit of a more convenient size. The symbol for the prefix is attached to the symbol for the unit, e.g., nanometer (nm) = 10−9 m. The units of mass are specified in terms of the gram, e.g., microgram (μg) = 10−9 kg.

Only one prefix is used with a unit; the use of units such as the millimicrometer is no longer acceptable. When a unit is raised to a power, the power applies to the prefix as well, e.g., a cubic millimeter (mm3) = 10−9 m3. When a prefix is used with a ratio unit, it should be in the numerator rather than in the denominator, e.g., kilometers/second (km/s) rather than meters/millisecond (m/ms). Only prefixes denoting powers of 103 are normally used. Hecto-, deka-, deci-, and centi- are usually attached only to the metric system units gram, meter, and liter.

Owing to the force of tradition, one noncoherent unit, the liter, equal to 10−3 m3, or 1 dm3, is generally accepted for use with SI. The internationally accepted abbreviation for liter is the letter l; however, this can be confused with the numeral 1, especially in typescript. For this reason, the capital letter L is also used as a symbol for liter. The lower case letter is generally used with prefixes, e.g., dl, ml, fl. The symbols for all other SI units begin with a capital letter if the unit is named after a person and with a lower case letter otherwise. The name of a unit is never capitalized.

Kel·vin

(kel'vĭn),
William Thomson, Scottish physicist, 1824-1907. See: kelvin, Kelvin scale.

kel·vin (K),

(kel'vĭn),
A unit of thermodynamic temperature equal to 273.16-1 of the thermodynamic temperature of the triple point of water. See: Kelvin scale.
[Lord Kelvin]

kel·vin

(K) (kel'vin)
A unit of thermodynamic temperature equal to 1/273.16 of the thermodynamic temperature of the triple point of water.
See also: Kelvin scale
[Lord Kelvin]
References in periodicals archive ?
Kelvin founded Ted Baker in Glasgow in 1987 and expanded the brand across the UK and US before it listed on the London Stock Exchange 10 years later.
Kelvin and Angel have their respective idols in the industry.
With the late Obediah not knowing the intent of his friend, he decided to go home after the rain had stopped, but while on his way, suspect Kelvin emerged from the dark and stabbed him.
Kelvin named his business, one of Britain's best-known fashion brands, after a fictitious alter ego, and the "hug culture" that he fostered in his office was well known.
Ma' pethau'n anodd i bawb rwan, yn enwedig ar Kelvin a'r plant cyn y Nadolig.
567, 568 (2005), of producing some credible evidence of changed circumstances since the initial guardianship determination, such that Kelvin may no longer be in need of a guardian.
Police said the 19-year-old used a kitchen knife to kill Kelvin Ikatwa, 25, at 3.30pm, moments after he arrived at her house in Kangemi.
Synopsis: "Kelvin, Thermodynamics and the Natural World" offers a detailed survey of the life and works of Lord Kelvin, including his standing and relationships with Charles Darwin, T.
Out West, you know a very chilly morning can turn into a warm afternoon--especially with all the up and down hiking you're doing in pursuit of your game, The perfect garments for this situation are in the Kelvin Lite series from Sitka Gear.
HAVE YOUR SAY The news of Kelvin Mac-Kenzie's return to the paper has been met by anger and criticism on social media by supporters of the Hillsborough victims' families.