Unit symbols are case sensitive. The following are the units that are distributed with the Loom 4.0 release. Each entry specifies the base unit for the measure, and the other units that are defined. These units can be composed to form any arbitrary combination. The syntax for dimensioned numbers is to have the numeric value immediately followed by the units expression, with no intervening speaces. Measurement units are delimited by exponents or the period symbol (".") The division slash "/" may appear once in a unit specification. As an example, the following are three alternate ways of specifying 12 square meters per second: 12m.m/s 12m2/s 12m2s-1 SUMMARY OF MEASURES. Base unit is the base unit for that measure. Kind is either fundamental or derived. Derived units have a definition in terms of other units. Name Base Unit Kind ===================== ========= =========== DISTANCE-MEASURE m Fundamental AREA-MEASURE m2 Derived VOLUME-MEASURE m3 Derived TIME-MEASURE s Fundamental SPEED-MEASURE m/s Derived ACCELERATION-MEASURE m/s2 Derived ANGLE-MEASURE deg Fundamental MASS-MEASURE kg Fundamental FORCE-MEASURE N Derived PRESSURE-MEASURE Pa Derived DENSITY-MEASURE kg/m3 Derived POWER-MEASURE W Derived WORK-OR-TORQUE-MEASURE J Derived REVOLUTION-MEASURE deg/s Derived FREQUENCY-MEASURE Hz Derived ELECTRIC-CURRENT-MEASURE A Fundamental ELECTRIC-CHARGE-MEASURE C Derived ELECTRIC-POTENTIAL-MEASURE V Derived ELECTRIC-RESISTANCE-MEASURE ohm Derived CAPACITANCE-MEASURE F Derived INDUCTANCE-MEASURE H Derived MAGNETIC-FLUX-MEASURE Wb Derived MAGNETIC-FLUX-DENSITY-MEASURE T Derived LUMINOUS-INTENSITY-MEASURE Cd Fundamental ILLUMINANCE-MEASURE lux Derived DATA-MEASURE bit Fundamental TEMPERATURE-MEASURE K Fundamental SCALAR-MEASURE Fundamental FULL SPECIFICATION OF MEASURES. This table lists the measures, their base units and definitions, and the units that have been defined for use by users. The unit definitions will include the name and sometimes other notes about the units available. The only areas where things get a little tricky is with the Data-measure and the Temperature-Measure. Although the system is largely base on the SI system of measures, we have added many non-SI units in order to make the package as useful as possible. The choice of non-SI units does have a strong U.S. bias. DISTANCE-MEASURE base unit: m (Meter) units: nm (nanometer) um (micrometer) mm (millimeter) cm (centimeter) dm (decimeter) km (kilometer) angstrom ang (angstrom) in (inch, international) Standard U.S. measure ft (foot, international) Standard U.S. measure yd (yard, international) Standard U.S. measure mile (mile, international Standard U.S. measure miles (mile) mi (mil) NM (nautical mile) lower case already taken nautmi (nautical mile) fathom furlong pica (pica) computer, not printer's point (point) computer, not printer's pt (point) AU (Astronomical Unit) lightyear Derived from year and c LY (light year) parsec AREA-MEASURE base unit: m2 (Square Meter) :units (mm2 cm2 km2 Obvious derivations in2 yd2 ft2 mile2 NM2 sqyd (square yard) sqft (square foot) sqin (square inch) sqkm (square kilometer) sqmile (square mile) hectare ha (hectare) are a (are) acre VOLUME-MEASURE base unit: m3 (Cubic meter) :units liter l (liter) ml (millileter) cc (cubic centimeter) cl (centiliter) dl (deciliter) Hl (hektoliter) cuft (cubic foot) cuyd (cubic yard) mm3 cm3 km3 Obvious derivations in3 ft3 yd3 mile3 NM3 acrefeet (acre foot) gallon (gallon, U.S.) Not Imperial pint (pint, U.S.) Not Imperial quart (quart, U.S.) Not Imperial gal (gallon, U.S.) Not Imperial qt (quart, U.S.) Not Imperial floz (fluid ounce) cup (cup) tbl (tablespoon) tsp (teaspoon) barrel (barrel, petroleum) bbl (barral) Mbbl (million barrels) 10^6 Bbbl (billion barrels) 10^9, U.S. billion BRT (Brutto register ton) Register ton TIME-MEASURE base unit: s (second) :units ns (nanosecond) us (microsecond) ms (millisecond) min (minute) "m" is taken for meter h (hour) hr (hour) day (day) days week (week) weeks fortnight year (mean tropical year) 365.24219 days years decade century SPEED-MEASURE base unit: m/s (meters per second) :units km/h mph kts ft/s knots c ; Speed of Light ; NIST, MfM ACCELERATION-MEASURE base unit: m/s2 (meters per second squared) :units G (Gee) acceleration due to 1 gravity This permits use of standard gravitational acceleration as if it were a unit. ft/s2 (feet per second squared) ANGLE-MEASURE base unit: deg (degree) :units rad (radian) minute (minute of arc) sec (second of arc) mil (mil of angle) There are 6400 mils in a circle Notes: The Angle-Measure uses degrees as the fundamental unit rather than the SI standard of radians. This was done to make conversions between degrees and minutes and seconds exact, since the conversion between radians and degrees involves the use of the irrational number PI. MASS-MEASURE base unit: kg (kilogram) :units g (gram) mg (milligram) ug (microgram) lbs (pounds, avoidupois) lb (pounds, avoidupois) oz (ounces, avoidupois) gr (grain) mton (metric ton) tonne (metric ton) tonshort (ton, U.S. short) 2000 lbs longton (ton, U.S. long) 2240 stone (stone) hwt (hundredweight) slug (slug) carat (carat) Jewelers FORCE-MEASURE base unit: N (Newton) Definition: kg.m/s2 :units g.m/s2 kN (kilonewton) kgf (kilogram of force) lbf (pound of force) dyne (dyne) PRESSURE-MEASURE base unit: Pa (Pascal) Definition: kg/s2m :units g/s2m N/m2 (Newton per square meter) hPa (hectopascal) kPa (kilopascal) atm (atmosphere) Normal sea level air pressure inHg (inches of mercury) torr (torr) mmHg (millimeters of mercury) psi (pounds per square inch) bar (bar) mbar (millibar) DENSITY-MEASURE base unit: kg/m3 (kilograms per cubic meter) :units g/m3 (grams per cubic meter) g/cm3 (grams per cubic centimeter) lbs/in3 (pounds per cubic inch) POWER-MEASURE base unit: W (Watt) Definition: m2kg/s3 :units N.m/s (Newton-meter per second) mW (milliwatt) kW (kilowatt) MW (megawatt) GW (gigawatt) hp (horsepower) shp (shaft horsepower) WORK-OR-TORQUE-MEASURE base unit: J (Joule) Definition: m2kg/s2 :units N.m (Newton-meter) Preferred unit for torque ft.lbf (foot-pound) Note: pound-force, not mass in.lbf (inch-pount) Note: pound-force, not mass kJ (kilojoule) MJ (megajoule) GJ (gigajoule) BTU (British Thermal Unit, international) cal (calorie, international) kcal (kilocalorie) therm (therm) EC definition, not US kWh (kilowatt-hour) Notes: Torque has the same units as work, so we cannot distinguish between them BTU and calorie have several different values. We have chosen to use the international BTU and calorie. REVOLUTION-MEASURE base unit: deg/s (degrees per second) :units rps (revolutions per second) 360deg/sec rpm (revolutions per minute) 360deg/min FREQUENCY-MEASURE base unit: Hz (Hertz) Definition: s-1 :units kHz (kilohertz) MHz (megahertz) GHz (gigahertz) ELECTRIC-CURRENT-MEASURE base unit: A (Ampere) :units mA (milliampere, milliamp) ELECTRIC-CHARGE-MEASURE base unit: C (Coulomb) Definition: s.A :units pC (picocoulomb) ELECTRIC-POTENTIAL-MEASURE base unit: V (Volt) Definition: m2kg/s3A = W/A :units mV (millivolt) kV (kilovolt) MV (megavolt) ELECTRIC-RESISTANCE-MEASURE base unit: ohm (Ohm) Definition: m2kg/s3A2 = V/A :units kohm (kiloohm) Mohm (megaohm) CAPACITANCE-MEASURE base unit: F (Farad) Definition: A2s4/m2kg = C/V :units mF (millifarad) uF (microfarad) pF (picofarad) INDUCTANCE-MEASURE base unit: H (Henry) Definition: m2kg/A2s2 = Wb/A MAGNETIC-FLUX-MEASURE base unit: Wb (Weber) Definition: m2kg/s2A = V.s MAGNETIC-FLUX-DENSITY-MEASURE base unit: T (Tesla) Definition: kg/s2A = Wb/m2 LUMINOUS-INTENSITY-MEASURE base unit: Cd (Candela) :units lumen (lumen) lm (lumen) Notes: Also includes luminous flux, which has the same reduced units. ILLUMINANCE-MEASURE base unit: lux Definition: Cd/m2 :units lx (lux) DATA-MEASURE base unit: bit (one bit) :units byte (byte) 8 bits BASE 2 Multiples: kibit (kibibit) 2^10 bits Kibit (kibibit) Mibit (mibibit) 2^20 bits KiB (kibibyte) 2^10 bytes kiB (kibibyte) MiB (mebibyte) 2^20 bytes GiB (gibibyte) 2^30 bytes TiB (tebibyte) 2^40 bytes BASE 10 Multiples: kbit (kilobit) 10^3 bits Mbit (megabit) 10^6 bits kB (kilobyte) 10^3 bytes MB (megabyte) 10^6 bytes GB (gigabyte) 10^9 bytes TB (terabyte) 10^12 bytes Note: The standard metri prefixes should only be used for multiples of 10. For binary multiples, other related prefixes need to be used. We use the prefixes for binary multiples that have been adopted by the International Electrotechnical Commission for use in information technology. See http://physics.nist.gov/cuu/Units/binary.html TEMPERATURE-MEASURE base unit: K (degree kelvin) :units F (degree Fahrenheit) C (degree Celsius) or Centigrade R (degree Rankine) Fahrenheit counterpart to Kelvin Note: The temperature measure differs from all the others in that it is linked to a scale with different zero points for various measures. That means that this measure can only be used for describing the absolute temperature of items. It cannot correctly be used in computations other than unit conversions since it is tied to this outside scale. In other words, don't add or subtract temperatures! SCALAR-MEASURE :units % (percent) 1/100 %% (promille) 1/1000 Note: All numbers without units belong to the scalar measure, even if not specifically enumerated. This measure class is used to allow the reader mechanism to support things like percent and promille. =============================================================================== References: Guide for the Use of the International System of Units (SI) U.S. Department of Commerce National Institute of Standards and Technology (NIST) NIST Special Publication 811, 1995 Edition http://physics.nist.gov/Document/sp811.pdf Richard A. Young and Thomas J. Glover Measure for Measure 1996. ISBN 1-889796-00-X (Blue Willow, Inc.; Littleton, Colorado, USA) http://www.bluewillow.com