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unit of measure |
A standard of measurement for some dimension. For example, the Meter is a UnitOfMeasure for the dimension of length, as is the Inch. There is no intrinsic property of a UnitOfMeasure that makes it primitive or fundamental, rather, a system of units (e.g. SystemeInternationalUnit) defines a set of orthogonal dimensions and assigns units for each.
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| Instances | ampere | SI electric current measure. Symbol: s. It is one of the base units in SI. It is defined as follows: the Ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 Meter apart in a vacuum, would produce between these conductors a force equal to 2*10^(-7) Newton per Meter of length. |
| | becquerel | SI radioactivity measure. Symbol: Bq. It measures the amount of radioactivity contained in a given sample of matter. It is that quantity of a radioactive element in which there is one atomic disintegration per SecondDuration. Becquerel = s^(-1). |
| | candela | SI luminosity intensity measure. Symbol: cd. It is one of the base units in SI, and it is currently defined as follows: the Candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540*10^12 Hertz and that has a radiant intensity in that direction of 1/683 Watt per Steradian. |
| | celsius degree | A TemperatureMeasure. The freezing point and the boiling point of water are, respectively, 0 CelsiusDegrees and 100 CelsiusDegrees. |
| | coulomb | SI electric charge measure. Symbol: C. It is the quantity of electric charge transported through a cross section of a conductor in an electric circuit during each SecondDuration by a current of 1 Ampere. Coulomb = s*A. |
| | farad | SI capacitance measure. Symbol: F. It is the capacitance of a capacitator between the plates of which there appears a difference of potential of 1 Volt when it is charged by a quantity of electricity equal to 1 Coulomb. Farad = C/V = m^(-2)*kg(-1)*s^4*A^2. |
| | gram | Submultiple of kilogram. Symbol: g. 1 kilogram = 1000 Grams. |
| | gray | SI absorbed dose measure. Symbol: Gy. It measures the dose of radiation absorbed in living tissue. It is equal approximately to the absorbed dose delivered when the energy per unit mass imparted to matter by ionizing radiation is 1 Joule per kilogram. Gray = J/kg = m^2*s^(-2). |
| | henry | SI inductance measure. Symbol: H. One Henry is equivalent to one Volt divided by one Ampere per SecondDuration. If a current changing at the rate of one Ampere per SecondDuration induces an electromotive force of one Volt, the circuit has an inductance of one Henry. Henry = Wb/A = m^2*kg*s^(-2)*A^(-2). |
| | hertz | SI frequency measure. Symbol: Hz. It is the number of cycles per second. Hertz = s^(-1). Note that Hertz does not have a conversion function. |
| | joule | SI energy measure. Symbol: J. It is the work done when the point of application of 1 Newton is displaced a distance of 1 Meter in the direction of the force. Joule = N*m = m^2*kg*s^(-2). |
| | kelvin degree | SI UnitOfMeasure used with MeasureFn to produce terms denoting instances of TemperatureMeasure. Symbol: K. It is one of the base units in SI (it is also a unit in the ITS system). Kelvin differs from the Celsius scale in that the triple point of water is defined to be 273.16 KelvinDegrees while it is 0 CelsiusDegrees. The magnitudes of intervals in the two scales are the same. By definition the conversion constant is 273.15. |
| | kilogram | Supermultiple of Gram. Symbol: kg. 1 Kilogram = 1000 Grams. |
| | lumen | SI luminous flux measure. Symbol: lm. It is the amount streaming outward through one solid angle of 1 Steradian from a uniform point source having an intensity of one Candela. Lumen = cd*sr = cd * 1. |
| | lux | SI illuminance measure. Symbol: lx. It is the amount of illumination provided when one Lumen is evenly distributed over an area of 1 square Meter. This is also equivalent to the illumination that would exist on a surface all points of which are one Meter from a point source of one Candela. Lux = lm/m^2 = m^(-2)*cd. |
| | meter | SI UnitOfLength. Symbol: m. It is one of the base units in SI, and it is currently defined as follows: the Meter is the length of the path traveled by light in a vacuum during a time interval of 1/299792458 of a SecondDuration. |
| | mole | SI amount of substance unit. symbol: mol. It is one of the base units in SI. It is defined as follows: the Mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 Kilograms of carbon 12. Note that, when this UnitOfMeasure is used, the elementary entities must be specified - they may be atoms, molecules, ions, electrons, etc. or groups of such particles. |
| | newton | SI force measure. Symbol: N. It is that force which gives to a mass of 1 kilogram an acceleration of 1 Meter per SecondDuration. Newton = m*kg*s^(-2). |
| | ohm | SI electric resistance measure. It is the electric resistance between two points of a conductor when a constant difference of potential of 1 Volt, applied between these two points, produces in this conductor a current of 1 Ampere, this conductor not being the force of any electromotive force. Ohm = V/A = m^2*kg*s^(-3)*A^(-2). |
| | pascal | SI pressure measure. Symbol:Pa. It is the pressure of one Newton per square Meter. Pascal = N/m^2 = m^(-1)*kg*s^(-2). |
| | radian | SI plane angle measure. Symbol: rad. It is the angle of a circle subtended by an arc equal in length to the circle's radius. Another definition is: the plane angle between two radii of a circle which cut off on the circumference an arc equal in length to the radius. Radian = m/m = 1. |
| | second duration | SI UnitOfDuration. Symbol: s. It is one of the base units in SI, and it is currently defined as follows: the SecondDuration is the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. |
| | siemens | SI electric conductance measure. Symbol: S. In the case of direct current, the conductance in Siemens is the reciprocal of the resistance in Ohms, in the case of alternating current, it is the reciprocal of the impedance in ohms. siemens = A/V = m^(-2)*kg(-1)*s^(3)*A^2. |
| | sievert | SI dose equivalent measure. Symbol: Sv. It is a unit of biologic dose of ionizing radiation. The Sievert makes it possible to normalize doses of different types of radiation. It takes into account the relative biologic effectiveness of ionizing radiation, since each form of such radiation--e.g., X rays, gamma rays, neutrons-- has a slightly different effect on living tissue for a given absorbed dose. The dose equivalent of a given type of radiation (in Sievert) is the dose of the radiation in Gray multiplied by a quality factor that is based on the relative biologic effectiveness of the radiation. Accordingly, one Sievert is generally defined as the amount of radiation roughly equivalent in biologic effectiveness to one Gray of gamma radiation. Sievert = J/kg = m^2*s^(-2). |
| | steradian | SI solid angle measure. Symbol: sr. It is the solid angle of a sphere subtended by a portion of the surface whose area is equal to the square of the sphere's radius. Another definition is: the solid angle which, having its vertex in the center of the sphere, cuts off an area of the surface of the sphere equal to that of a square with sides of length equal to the radius of the sphere. Steradian = m^2/m^2 = 1. |
| | tesla | SI magnetic flux density measure. Symbol: T. One Tesla equals one Weber per square Meter. Tesla = Wb/m^2 = kg*s^(-2)*A^(-1). |
| | volt | SI electric potential measure. Symbol: V. It is the difference of electric potential between two points of a conducting wire carrying a constant current of 1 Ampere, when the power dissipated between these points is equal to 1 Watt. Volt = W/A = m^2*kg*s^(-3)*A^(-1). |
| | watt | SI power measure. Symbol: W. A UnitOfMeasure that measures power, i.e. energy produced or expended divided by TimeDuration. It is the power which gives rise to the production of energy (or work) at the rate of one Joule per SecondDuration. Watt = J/s = m^2*kg*s^(-3). |
| | weber | SI magnetic flux measure. Symbol: Wb. It is the magnetic flux which, linking a circuit of one turn, produces in it an electromotive force of 1 Volt as it is reduced to zero at a uniform rate in 1 SecondDuration. Weber = V*s = m^2*kg*s^(-2)*A^(-1). |