RP66 units are character strings obeying certain rules. The strings may be any drawn from a list defined as part of the standard, or they may be expressions involving such units. This section contains a table of units explicitly defined in RP66, followed by some examples of unit expressions. A full description of unit expressions can be found in appendix B.27 of the RP66 standard. Case is significant for all units and unit expressions.
As examples of the use of units, to indicate that an attribute value has units percent, encode its unit characteristic as "%"; to indicate that a measurement has units degrees Celsius, encode the unit as "degC."
Following the example from the previous section, to indicate meters for a DISTANCE-UNIT attribute, encode the attribute value as "m".
Unit Examples Unit | Unit Expression | Unit Name | % | 0.01 | percent | A | A | ampere | B | 10 dB | bel | Bq | 1/s | becquerel | Btu | 1055.05585262 J | British thermal unit (international) | C | A.s | coulomb | D | 0.9869233 um2 | darcy | EJ | 1E18 J | exajoule | F | C/V | farad | GBq | 1E9 Bq | gigabecquerel | GHz | 1E9 Hz | gigahertz | GJ | 1E9 J | gigajoule | GPa | 1E9 Pa | gigapascal | GS | 1E9 S | gigasiemens | GW | 1E9 W | gigawatt | Gal | cm/s2 | galileo | GeV | 1E9 eV | gigaelectronvolt | Gohm | 1E9 ohm | gigaohm | Grad | 1E9 rad | gigaradian | Gy | J/kg | gray | H | Wb/A | henry | Hz | 1/s | hertz | J | N.m | joule | K | K | kelvin | L | dm3 | liter | MA | 1E6 A | megampere | MBq | 1E6 Bq | megabecquerel | MHz | 1E6 Hz | megahertz | MJ | 1E6 J | megajoule | MN | 1E6 N | meganewton | MPa | 1E6 Pa | megapascal | MV | 1E6 V | megavolt | MW | 1E6 W | megawatt | Ma | 1E6 a | million years | MeV | 1E6 eV | megaelectronvolt | Mg | 1000 kg | megagram | Mm | 1E6 m | megameter | Mohm | 1E6 ohm | megohm | Mpsi | 1E6 psi | million pounds per square inch | Mrad | 1E6 rad | megaradian | N | kg.m/s2 | newton | Oe | 79.57747 A/m | oersted | P | 0.1 Pa.s | poise | Pa | N/m2 | pascal | S | A/V | siemens | Sv | J/kg | sievert | T | Wb/m2 | tesla | TBq | 1E12 Bq | terabecquerel | TJ | 1E12 J | terajoule | TW | 1E12 W | terawatt | TeV | 1E12 eV | teraelectronvolt | Tohm | 1E12 ohm | teraohm | V | W/A | volt | W | J/s | watt | Wb | V.s | weber | a | 3.155815E7 s | annum (sidereal year) | aJ | 1E-18 J | attojoule | acre | 627264E5/15499969 m2 | acre | ag | 1E-18 g | attogram | atm | 101.325 kPa | standard atmosphere | b | 1E-28 m2 | barn | bar | 100 kPa | bar | bbl | 0.158987304 m3 | barrel | c | 360 deg | revolution (cycle) | cP | 0.01 P | centipoise | cal | 4.1868 J | calorie (international) | cd | cd | candela | cm | 0.01 m | centimeter | cu | 0.1 1/m | capture unit | d | 24 h | day | dAPI | dAPI | api density | dB | dB | decibel | daN | 10 N | decanewton | deg | 0.0174532925198 | rad degree (angle) | degC | K -273.15 | degree Celsius | degF | 5/9 degC +32 | degree Fahrenheit | degR | 5/9 K | degree Rankine | dm | 0.1 m | decimeter | eV | 1.60219E-19 J | electron volt | fC | 1E-15 C | femtocoulomb | fm | 1E-15 m | femtometer | ft | 12 in | foot | g | 0.001 kg | gram | gAPI | gAPI | api gamma ray | gal | 1/42 bbl | gallon | gf | 0.001 kgf | gram force | h | 60 min | hour | hL | 100 L | hectoliter | ha | 1E4 m2 | hectare | hbar | 100 bar | hectobar | hp | 745.699871580 W | horsepower | in | 0.0254 m | inch | kA | 1000 A | kiloampere | kC | 1000 C | kilocoulomb | kHz | 1000 Hz | kilohertz | kJ | 1000 J | kilojoule | kN | 1000 N | kilonewton | kPa | 1000 Pa | kilopascal | kS | 1000 S | kilosiemens | kV | 1000 V | kilovolt | kW | 1000 W | kilowatt | kcal | 1000 cal | kilocalorie | kcd | 1000 cd | kilocandela | keV | 1000 eV | kiloelectronvolt | kg | kg | kilogram | kgf | 9.806650 N | kilogram force | klx | 1000 lx | kilolux | km | 1000 m | kilometer | kmol | 1000 mol | killomole | kohm | 1000 ohm | kilohm | krad | 1000 rad | kiloradian | lbf | 4.4482216152605 N | pound force | lbm | 0.45359237 kg | pound mass (avoirdupois) | lm | cd.sr | lumen | lx | cd.sr/m2 | lux | m | m | meter | mA | 0.001 A | milliampere | mC | 0.001 C | millicoulomb | mD | 0.9869233E-3 um2 | millidarcy | mGal | 0.001 Gal | milligal | mGy | 0.001 Gy | milligray | mH | 0.001 H | millihenry | mHz | 0.001 Hz | millihertz | mJ | 0.001 J | millijoule | mL | 0.001 L | milliliter | mN | 0.001 N | millinewton | mPa | 0.001 Pa | millipascal | mS | 0.001 S | millisiemens | mSv | 0.001 Sv | millisievert | mT | 0.001 T | millitesla | mV | 0.001 V | millivolt | mW | 0.001 W | milliwatt | mWb | 0.001 Wb | milliweber | mbar | 0.001 bar | millibar | mg | 0.001 g | milligram | mi | 5280 ft | mile | min | 60 s | minute | minarc | 1/60 deg | minute of arc | mm | 0.001 m | millimeter | mmol | 0.001 mol | millimole | mohm | 0.001 ohm | milliohm | mol | mol | mole | mrad | 0.001 rad | milliradian | ms | 0.001 s | millisecond | nA | 1E-9 A | nanoampere | nAPI | nAPI | api neutron | nC | 1E-9 C | nanocoulomb | nH | 1E-9 H | nanohenry | nJ | 1E-9 J | nanojoule | nT | 1E-9 T | nanotesla | nW | 1E-9 W | nanowatt | nm | 1E-9 m | nanometer | nohm | 1E-9 ohm | nanohm | ns | 1E-9 s | nanosecond | ohm | V/A | ohm | ozf | 1/16 lbf | ounce force | ozm | 1/16 lbm | ounce mass | pA | 1E-12 A | picoampere | pC | 1E-12 C | picocoulomb | pF | 1E-12 F | picofarad | pPa | 1E-12 Pa | picopascal | pS | 1E-12 S | picosiemens | pm | 1E-12 m | picometer | ppdk | 1E-4 | part per ten thousand | ppk | 0.001 | part per thousand | ppm | 1E-6 | part per million | ps | 1E-12 s | picosecond | psi | lbf/in2 | pound per square inch | pu | 0.01 m3/m3 | porosity unit | rad | rad | radian | s | s | second | secarc | 1/3600 deg | second of arc | sr | sr | steradian | t | 1000 kg | metric ton (1000 kilograms) | ton | 2000 lbm | U.S. short ton | uA | 1E-6 A | microampere | uC | 1E-6 C | microcoulomb | uF | 1E-6 F | microfarad | uH | 1E-6 H | microhenry | uHz | 1E-6 Hz | microhertz | uJ | 1E-6 J | microjoule | uN | 1E-6 N | micronewton | uPa | 1E-6 Pa | micropascal | uS | 1E-6 S | microsiemens | uT | 1E-6 T | microtesla | uV | 1E-6 V | microvolt | uW | 1E-6 W | microwatt | uWb | 1E-6 Wb | microweber | ubar | 1E-6 bar | microbar | ug | 1E-6 g | microgram | um | 1E-6 m | micrometer | umol | 1E-6 mol | micromole | uohm | 1E-6 ohm | microhm | upsi | 1E-6 psi | micropound per square inch | urad | 1E-6 rad | microradian | us | 1E-6 s | microsecond | |
The following are some examples of units expressed in terms of other units:
Composite Units Unit | Unit Expression | Unit Name | 0.001 c/ft | 0.001 c/ft | revolution per thousand feet | 0.01 gal/ft2 | 0.01 gal/ft2 | gallon per hundred square feet | 1.12 ton | 1.12 ton | U.K. long ton | 1/N | 1/N | inverse newton | 1000 bbl.ft/d | 1000 bbl.ft/d | thousand (barrel per day)-foot | 1E-5 N | 1E-5 N | dyne | 1E-5 N/cm | 1E-5 N/cm | dyne per centimeter | 1E-5 Oe | 1E-5 Oe | gamma | A/cm2 | A/cm2 | ampere per square centimeter | MPa2 | MPa2 | megapascal squared | N.m | N.m | newton-meter | s/kg | s/kg | second per kilogram | |
Part of the RP66 appendix (B.27) on unit expressions states "The units expression is either a multiplicative combination of distinct units factors, or a numerator and denominator, each of which is a multiplicative combination of distinct units factors". Since the "distinct" requirement appears, exponents should be used to show higher powers of a unit rather than repeating the unit name in the expression.
Unit Preferences Use | In Preference to | m2 | m.m | m3 | m.m.m | m3 | m2.m | |
Last modified: 2002/12/19 11:04:22 CST.
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