This page is part of a series detailing the SI units and our calibration services. This article centers around acoustics. Sound has different parameters. Major parameters are sound frequency, sound intensity and sound pressure.For more information about
This page is part of a series detailing the SI units and our calibration services. This article centers around time and frequency.For more information about time and frequency calibrations, click here.
2 An introduction to SI units 12 2.1 The set of SI base units 12 2.2 The set of SI derived units 12 2.3 Non-SI units currently accepted for use with SI units 13 2.4 Other non-SI units 14 2.5 Prefixes to SI units 14 2.6 IAU recommendations regarding SI units 20 2.7 Summary and reco...
Frequency combNowadays, most of the standards of measurement are based on fundamental constants, and among all, the SI units of time and frequency are realized with the highest precision. The SI unit of time interval, i.e. second, is realized on the basis of a hyperfine transition of ...
type Hz A synonym for hertz, the SI unit of frequency. type J A synonym for joule, the SI unit of energy, work, amount of heat. type K A synonym for kelvin, the SI unit of thermodynamic (absolute) temperature. type kat A synonym for katal, the SI unit of catalytic activity. type...
Some derived units are given unique names. AmountUnit nameUnit symbolComposition FrequencyHertzHz1Hz=1s-1 ForceNewtonN1N=1kg･m/s2 Pressure, stressPascalPa1Pa=1N/m2 Energy, work, amount of heatJouleJ1J=1N･m Power, radiant fluxWattWW=1J/s ...
The International System of Units (abbreviated SI Units from the French Système international d’unités) is the modern form of the metric system and is
Units SI UnitsPlane angle radian rad m/mFrequency hertz Hz s\11Force newton N kg m/s2 J/mPressure pascal Pa kg/m s2 N/m2Energy; work joule J kg m2/s2 N mPower watt W kg m2/s3 J/sElectric charge coulomb C A sElectric potential volt V kg m2/ A s3 W/ACapacitance farad F A2...
能量单位：焦耳 符号J 电能单位：焦耳（J）或者“千瓦.时（kw.h）”或者“度” 1kw.h=1度
TABLE D.2 Some Derived SI UnitsExpression in Expression inTerms of Base Terms of OtherQuantity Name Symbol Units SI UnitsPlane angle radian rad m/mFrequency hertz Hz s\11Force newton N kg m/s2 J/mPressure pascal Pa kg/m s2 N/m2Energy; work joule J kg m2/s2 N mPower watt W kg ...