# Generated from udunits2-common.xml


# unit of time, synonym for second
# [comment] Synonym for SI unit
@alias second = sec = secs

# unit of electric current, synonym for ampere
# [comment] Synonym for SI unit
@alias ampere = amp = amps

# unit of temperature, synonym for kelvin
# [comment] Synonym for SI unit
# [comment @ °K] DEGREE SIGN
@alias kelvin = °K = degree_kelvin = degrees_kelvin = degree_K = degrees_K = degreeK = degreesK = deg_K = degs_K = degK = degsK

# unit of luminous intensity, synonym for candela
# [comment] Synonym for SI unit
@alias candela = candle = candles

# unit of chemical mass, synonym for mole
# [comment] Synonym for SI unit
@alias mole = einstein = einsteins

# unit of frequency, synonym for hertz
# [comment] Synonym for SI unit
@alias hertz = baud = bauds = Bd = bps

# unit of temperature, synonym for 'K @ 273.15' (degree_Celsius)
# [comment] Synonym for SI unit
# [comment @ ℃] DEGREE CELSIUS
@alias degree_Celsius = ℃ = celsius = celsiuses = degree_C = degrees_C = degreeC = degreesC = deg_C = degs_C = degC = degsC

# unit of speed, synonym for nautical_mile/hour
# [comment] Synonym for SI unit
kt = knot = kts

# number of constituent particles (usually atoms or molecules) per
# mole of a given substance
# [comment] Constant; value is +-30e15
avogadro_constant = 6.02214179e23 / mol = _

# number of parts per hundred
# [comment] Constant
percent = 0.01 = %

# parts per volume
# [comment] Constant
ppv = 1

# parts per million
# [comment] Constant
ppm = 1e-6 = ppmv

# parts per billion
# [comment] Constant
ppb = 1e-9 = ppbv

# parts per trillion
# [comment] Constant
ppt = 1e-12 = pptv

# parts per quadrillion
# [comment] Constant
ppq = 1e-15 = ppqv

# logarithmic unit used to express dimensionless ratios; a value of 0
# B (0 dB) corresponds to a ratio of 1
B = 1; logbase: 10; logfactor: 10

# 1/100 of a right angle (90 degrees)
grade = 0.9 * arc_degree = _ = grades

# unit of angle in a plane signifying a full 360-degree circle
circle = 2 * pi * rad = _ = circles = cycle = cycles = turn = turns = revolution = revolutions = rotation = rotations

# unit of angle on a sphere
@alias arc_degree = degree_north = degrees_north = degree_N = degrees_N = degreeN = degreesN = degree_east = degrees_east = degree_E = degrees_E = degreeE = degreesE = degree_true = degrees_true = degree_T = degrees_T = degreeT = degreesT

# unit of angle on a sphere (units for negative direction)
degree_west = -1 * degree_east = _ = degrees_west = degree_W = degrees_W = degreeW = degreesW

# reference unit of mass for a body of ore; roughly equal to 29167
# milligrams
assay_ton = 2.916667e-2 * kg = _ = assay_tons

# unit of mass equal to 1/16 avoirdupois pound, commonly used in the
# United States (16 oz = 1 pound = 7000 grains)
avoirdupois_ounce = 2.834952e-2 * kg = _ = avoirdupois_ounces

# unit of mass in avoirdupois system of weights (a system commonly
# used in United States)
avoirdupois_pound = 4.5359237e-1 * kg = lb = avoirdupois_pounds = pound = pounds

# unit of mass equal to 0.2 gram (defined 1907)
carat = 2e-4 * kg = _ = carats

# unit of mass equal to 1/7000 pound
grain = 6.479891e-5 * kg = gr = grains

# unit of mass; a British hundredweight, which is 8 stone * 14
# pounds/stone
long_hundredweight = 5.080235e1 * kg = _ = long_hundredweights

# unit of mass; based on historical US troy weight system (is 1/20
# troy ounce)
pennyweight = 1.555174e-3 * kg = _ = pennyweights

# unit of mass, a US hundredweight, which is 100 pounds
short_hundredweight = 4.535924e1 * kg = _ = short_hundredweights

# unit of mass associated with Imperial units; a mass that accelerates
# by 1 ft/s2 when a force of one pound-force (lbF) is exerted on it
slug = 14.59390 * kg = _ = slugs

# unit of mass; based on historical US troy weight system (is 1/12
# troy pound)
troy_ounce = 3.110348e-2 * kg = _ = troy_ounces = apothecary_ounce = apothecary_ounces

# unit of mass; based on historical US troy weight system (is 5760
# grain)
troy_pound = 3.732417e-1 * kg = _ = troy_pounds = apothecary_pound = apothecary_pounds

# unit of mass in apothecaries' weight system (is 1/3 apdram)
scruple = 20 * grain = _ = scruples

# unit of mass in apothecaries' weight system (is 1/8 apounce)
apdram = 60 * grain = _ = apdrams

# unit of mass in the avoirdupois system (the system commonly used in
# the United States)
# [comment] exact
dram = avoirdupois_ounce / 16 = dr = drams

# unit of mass in apothecaries' weight system (is 1/16 appound)
apounce = 480 * grain = _ = apounces

# unit of mass in apothecaries' weight system (is same as a troy
# pound)
appound = 5760 * grain = _ = appounds

# unit of mass, for a traditional bag of portland cement
bag = 94 * pound = _ = bags

# unit of mass based on US weight system
short_ton = 2000 * pound = _ = short_tons = ton = tons

# unit of mass based on British imperial weight system
long_ton = 2240 * pound = _ = long_tons

# unit of length equal to 10e-15 meters, a typical length-scale of
# nuclear physics
fermi = 1e-15 * m = _ = fermis

# unit of length equal to the distance traversed by light in one mean
# solar year (365.2422 days), a typical length-scale of astronomy
light_year = 9.46073e15 * m = _ = light_years

# unit of length, a typical length-scale of technology and science
# fields
micron = 1e-6 * m = _ = microns

# unit of length equal to 0.001 inch, a typical length-scale for
# measuring wire diameters
mil = 2.54e-5 * m = _ = mils

# unit of length corresponding to the distance at which the mean
# radius of the earth's orbit subtends an angle of one second of arc,
# a typical length-scale of astronomy
parsec = 3.085678e16 * m = _ = parsecs

# unit of length equal to 1/72.27 inch, the original (standardized
# 1886) unit for measuring font size and other small items on a
# printed page (see also big_point)
printers_point = 3.514598e-4 * m = _ = printers_points

# unit of length equal to 66 feet (4 poles), or 1/10 furlong, a
# typical (historical) scale of land surveying
chain = 2.011684e1 * m = _ = chains

# unit of length equal to 1/6 inch (12 printers points)
printers_pica = 12 * printers_point = _ = printers_picas = pica = picas

# unit of length in the US Customary System, equal to 6,076 feet;
# typically used for air and sea navigation
nmile = nautical_mile = _ = nmiles

# unit of length used for earlier survey data in some countries,
# slightly different than the current international foot
US_survey_foot = (1200 / 3937) * m = _ = US_survey_feet

# unit of length used in earlier survey data in some countries,
# slightly different than the current international yard
US_survey_yard = 3 * US_survey_feet = _ = US_survey_yards

# unit of length used for earlier survey data in some countries,
# slightly slightly different than the current international mile
US_survey_mile = 5280 * US_survey_feet = _ = US_survey_miles = US_statute_mile = US_statute_miles

# unit of length equal to one-fourth of a surveyor's chain
rod = 16.5 * US_survey_feet = _ = rods = pole = poles = perch = perches

# unit of length equal to 1/8 mile or 10 chains
furlong = 660 * US_survey_feet = _ = furlongs

# unit of length equal to 6 feet in the imperial and US customary
# systems, typically used for measuring depth of water
fathom = 6 * US_survey_feet = _ = fathoms

# unit of length equal to 25.4 mm by definition, used in imperial and
# US customary systems
international_inch = 2.54 * cm = in = international_inches = inch = inches

# unit of length equal to 12 international inches, in the imperial and
# US customary systems; primarily used in the United States
international_foot = 12 * international_inches = ft = international_feet = foot = feet

# unit of length equal to 3 international feet, in the imperial and US
# customary systems; primarily used in the United States
international_yard = 3 * international_feet = yd = international_yards = yard = yards

# unit of length equal to 5280 feet, equal to 12 international inches,
# in the imperial and US customary systems; primarily used in the
# United States and other smaller countries with ties to the US or
# United Kingdom
international_mile = 5280 * international_feet = mi = international_miles = mile = miles

# unit of length equal to 1/72 inch, standardized unit in modern
# computer-based publishing for measuring font size and other small
# items on a printed page (contrast to printers_point)
big_point = inch / 72 = _ = big_points

# unit of length based in medieval laws of England and Wales, defining
# an inch as being 3 barleycorns long (length of a corn of barley);
# still the basis for current shoe sizes in Great Britain and Ireland
barleycorn = inch / 3 = _ = barleycorns

# unit of length in French regions; a linear arpent is of length 10
# perch (10 rod)
arpentlin = 191.835 * foot = _ = arpentlins

# unit of angular velocity
# [comment] exact
rotation_per_second = rotation / second = rps = rotations_per_second = cps

# unit of angular velocity measuring the angular distance covered by a
# rotating object, divided by the amount of time used to cover that
# distance; measured perpendicular to the plane of rotation, with
# direction usually indicated by the right-hand rule
# [comment] exact
rpm = rotation / minute

# unit of lineic mass density for fibers, equal to the mass in grams
# per 9000 meters (more common in United States and United Kingdom); a
# single strand of silk is approximately one denier
denier = 1.111111e-7 * kg / m = _ = deniers

# unit of lineic mass density for fibers, defined as mass in grams per
# 1000 meters (more common in Canada and Continental Europe)
# [comment] exact
tex = 1e-6 * kg / m = _ = texes

# unit of mass per unit time (includes flow) for how fast water vapor
# flows through substance, or permeance; equals 1 gram of water vapor
# per hour, per square meter, per millimeter of mercury at 0 degrees C
perm_0C = 5.72135e-11 * kg / (Pa * s * m ** 2) = _ = perms_0C

# unit of mass per unit time for how fast water vapor flows through
# substance, or permeance; equals 1 gram of water vapor per hour, per
# square meter, per millimeter of mercury at 23 degrees C
perm_23C = 5.74525e-11 * kg / (Pa * s * m ** 2) = _ = perms_23C

# unit of area equal to the area of a one-mil diameter circle
circular_mil = 5.067075e-10 * m ** 2 = _ = circular_mils

# unit of area for measuring permeability to fluid, equal to 1 cubic
# centimeter of fluid with 1 centipoise viscosity in 1 second through
# a 1-square-centimeter cross section of porous medium 1 centimeter
# long at 1 atmosphere
# [comment] porous solid permeability
darcy = 9.869233e-13 * m ** 2 = _ = darcies

# unit of area in the US Customary System, used in land and sea floor
# measurement, equal to 43560 square feet
# [comment] exact
acre = 160 * rod ** 2 = _ = acres

# unit of volume used to describe large-scale water resources in the
# United State; equal to the volume of one acre of surface area with
# one foot of depth depth
# [comment] An "acre.foot", however, is 1233.4867714897 m^3.  Odd.
acre_foot = 1.233489e3 * m ** 3 = _ = acre_feet

# unit of volume equal to the cubic contents of a piece of lumber one
# foot square and one inch thick, used in measuring logs and lumber in
# the United States and Canada
board_foot = 2.359737e-3 * m ** 3 = _ = board_feet

# unit of volume defined as 2150.42 cubic inches or 4 pecks in the US
# Customary system (and formerly in England), where it is used as a
# dry measure
bushel = 3.523907e-2 * m ** 3 = bu = bushels

# unit of volume defined as 537.6 cubic inches  in the US Customary
# system (and formerly in England), where it is used as a dry measure
# [comment] exact
peck = bushel / 4 = pk = pecks

# unit of volume for liquids in the Imperial system
# [comment] exact
Canadian_liquid_gallon = 4.546090e-3 * m ** 3 = _ = Canadian_liquid_gallons

# unit of volume for dry measure in the US Customary system, defined
# as 1/2 peck or 1/8 bushel
US_dry_gallon = 4.404884e-3 * m ** 3 = _ = US_dry_gallons

# unit of volume equal to the volume of a cube 1 centimeter on each
# side
# [comment] exact
cc = cm ** 3

# unit of volume equal to a cubic meter, originally defined primarily
# as a measure for firewood
# [comment] exact
stere = 1 * m ** 3 = _ = steres

# unit of volume used for internal capacity of ships, equal to 100
# cubic feet
register_ton = 2.831685 * m ** 3 = _ = register_tons

# unit of volume for dry measure in the US Customary system, equal to
# 1/32 US bushel
# [comment] exact
US_dry_quart = US_dry_gallon / 4 = _ = US_dry_quarts = dry_quart = dry_quarts

# unit of volume for dry measure in the US Customary system, equal to
# 1/2 US dry quart
# [comment] exact
US_dry_pint = US_dry_gallon / 8 = _ = US_dry_pints = dry_pint = dry_pints

# unit of volume for liquid measure in the US Customary system,
# defined as 3.785412 liters
US_liquid_gallon = 3.785412e-3 * m ** 3 = _ = US_liquid_gallons = liquid_gallon = liquid_gallons = gallon = gallons

# unit of volume used by US and Canadian petroleum organizations
# [comment] The following is the definition of the petroleum industry
barrel = 42 * US_liquid_gallon = bbl = barrels

# unit of volume whose exact quantity depends on the type of barrel on
# which it is defined; in this table it is defined based on the oil
# barrel used by the petroleum industry
# [comment] The following is exact regardless of the definition of
# "barrel"
firkin = barrel / 4 = _ = firkins

# unit of volume for liquid measure in the US Customary system, equal
# to 1/4 liquid gallon
# [comment] exact
US_liquid_quart = US_liquid_gallon / 4 = _ = US_liquid_quarts = liquid_quart = liquid_quarts = quart = quarts

# unit of volume for liquid measure in the US Customary system, equal
# to 1/8 liquid gallon
# [comment] exact
US_liquid_pint = US_liquid_gallon / 8 = pt = US_liquid_pints = liquid_pint = liquid_pints = pint = pints

# unit of volume for liquid measure in the US Customary system, equal
# to 1/16 liquid gallon
# [comment] exact
US_liquid_cup = US_liquid_gallon / 16 = _ = US_liquid_cups = liquid_cup = liquid_cups = cup = cups

# unit of volume for liquid measure in the US Customary system, equal
# to 1/32 liquid gallon
# [comment] exact
US_liquid_gill = US_liquid_gallon / 32 = _ = US_liquid_gills = liquid_gill = liquid_gills = gill = gills

# unit of volume for liquid measure in the US Customary system, equal
# to 1/128 liquid gallon
# [comment] exact
US_fluid_ounce = US_liquid_gallon / 128 = oz = US_fluid_ounces = US_liquid_ounce = US_liquid_ounces = fluid_ounce = fluid_ounces = liquid_ounce = liquid_ounces = floz

# unit of volume for liquid measure in the US Customary system, equal
# to 1/2 liquid ounce
# [comment] exact
tablespoon = US_fluid_ounce / 2 = Tbl = tablespoons = Tbsp = tbsp = Tblsp = tblsp

# unit of volume for liquid measure in the apothecary system, equal to
# 1/8 liquid ounce
# [comment] exact
fluid_dram = US_fluid_ounce / 8 = fldr = fluid_drams

# unit of volume defined as 1/3 tablespoon, the actual volume of which
# can vary depending on the measurement system (but is based on the US
# Customary system in this database)
# [comment] exact
teaspoon = tablespoon / 3 = tsp = teaspoons

# unit of volume for liquid measure in the Imperial system
# [comment] exact
UK_liquid_gallon = 4.546090e-3 * m ** 3 = _ = UK_liquid_gallons

# unit of volume for liquid measure in the Imperial system, equal to
# 1/4 liquid gallon
# [comment] exact
UK_liquid_quart = UK_liquid_gallon / 4 = _ = UK_liquid_quarts

# unit of volume for liquid measure in the Imperial system, equal to
# 1/8 liquid gallon
# [comment] exact
UK_liquid_pint = UK_liquid_gallon / 8 = _ = UK_liquid_pints

# unit of volume for liquid measure in the Imperial system, equal to
# 1/16 liquid gallon
# [comment] exact
UK_liquid_cup = UK_liquid_gallon / 16 = _ = UK_liquid_cups

# unit of volume for liquid measure in the Imperial system, equal to
# 1/32 liquid gallon
# [comment] exact
UK_liquid_gill = UK_liquid_gallon / 32 = _ = UK_liquid_gills

# unit of volume for liquid measure in the Imperial system, equal to
# 1/160 liquid gallon
# [comment] exact
UK_fluid_ounce = UK_liquid_gallon / 160 = _ = UK_fluid_ounces = UK_liquid_ounce = UK_liquid_ounces

# logarithmic unit used to compare the reflectivity (Z) of an unknown
# remote object, to the reflective return created by a rain with a
# density of a single drop with a diameter of 1 mm in every 1 m^3 of
# air; is the base unit for "dBz", which is the typical logarithmic
# unit for measuring atmospheric radar reflectivity; a value of 0 Bz
# (0 dBz) corresponds to the return from a single cubic micron; a
# value of 6 Bz (60 dBz) corresponds to extremely heavy rain.
BZ = (1e-6 * m) ** 3; logbase: 10; logfactor: 10 = Bz

# unit of time approximating the lifetime of an individual neutron,
# useful for describing very brief durations, e.g., in nuclear physics
shake = 1e-8 * s = _ = shakes

# unit of time that it takes the earth to complete one revolution with
# respect to a star, roughly 23 hours, 56 minutes, 4 seconds
sidereal_day = 8.616409e4 * s = _ = sidereal_days

# unit of time equal to 1/24 sidereal day
sidereal_hour = 3.590170e3 * s = _ = sidereal_hours

# unit of time equal to 1/60 sidereal hour
sidereal_minute = 5.983617e1 * s = _ = sidereal_minutes

# unit of time equal to 1/60 sidereal minute
sidereal_second = 0.9972696 * s = _ = sidereal_seconds

# unit of time for the earth to make one complete revolution around
# the sun, relative to the fixed stars
sidereal_year = 3.155815e7 * s = _ = sidereal_years

# unit of time; Interval between 2 successive passages of sun through
# vernal equinox (365.242198781 days). See
# http://www.ast.cam.ac.uk/pubinfo/leaflets/,
# http://aa.usno.navy.mil/AA/, and
# http://adswww.colorado.edu/adswww/astro_coord.html
tropical_year = 3.15569259747e7 * s = yr = tropical_years = year = years

# unit of time equal to the average time between successive new or
# full moons; equal to approximately 29 days, 12 hours, 44 minutes
lunar_month = 29.530589 * day = _ = lunar_months

# unit of time corresponding to a 'normal' calendar year, that is, one
# without insertion of a leap day
common_year = 365 * day = _ = common_years

# unit of time corresponding to a calendar year with a leap day
# inserted
leap_year = 366 * day = _ = leap_years

# unit of time recognized by the International Astronomical Union for
# use in astronomy, defined as 365.25 days of 86400 seconds
Julian_year = 365.25 * day = _ = Julian_years

# unit of time based on the Gregorian Calendar, the one commonly used
# today; approximates the tropical year as 365 + 97/400 days
Gregorian_year = 365.2425 * day = _ = Gregorian_years

# unit of time based on 1/12 of the sidereal year
sidereal_month = 27.321661 * day = _ = sidereal_months

# unit of time based on 1/12 of the tropical year
tropical_month = 27.321582 * day = _ = tropical_months

# unit of time commonly defined as 14 days
fortnight = 14 * day = _ = fortnights

# unit of time commonly defined as 7 days
week = 7 * day = _ = weeks

# unit of time used in computer animation as a method of defining
# playback rate
# [comment] multiple values have been proposed for the amount of time
# represented by a 'jiffy'
jiffy = 0.01 * s = _ = jiffies

# unit of time defined in astronomy as 1 billion years
eon = 1e9 * year = _ = eons

# unit of time defined as the average length of time for a calendar
# month
month = year / 12 = _ = months

# unit of volume transport, used almost exclusively to measure the
# volumetric rate of ocean currents
# [comment] exact
sverdrup = 1e6 * m ** 3 / s = _ = sverdrups

# unit of acceleration corresponding to the nominal gravitational
# acceleration of an object in a vacuum near the surface of earth
# [comment] exact
standard_free_fall = 9.806650 * m / s ** 2 = _ = standard_free_falls

# unit of acceleration synonymous with standard rate of free fall (in
# earth's gravity)
# [comment] should be local
gravity = standard_free_fall = _ = gravities

# specifies the acceleration at the earth's surface of a substance
# with the density of water
# [comment] exact
conventional_water = gravity * 1000 * kg / m ** 3 = H2O = conventional_waters = water = waters = h2o

# specifies the acceleration at the earth's surface of a substance
# with the density of water at 4 degrees C
water_4C = gravity * 999.972 * kg / m ** 3 = _ = waters_4C = water_39F = waters_39F

# specifies the acceleration at the earth's surface of a substance
# with the density of water at 60 degrees F
water_60F = gravity * 999.001 * kg / m ** 3 = _ = waters_60F

# specifies the acceleration at the earth's surface of a substance
# with the density of mercury at 0 degrees C
mercury_0C = gravity * 13595.10 * kg / m ** 3 = Hg = mercuries_0C = mercury_32F = mercuries_32F = conventional_mercury = conventional_mercuries

# specifies the acceleration at the earth's surface of a substance
# with the density of mercury at 60 degrees F
mercury_60F = gravity * 13556.8 * kg / m ** 3 = _ = mercuries_60F

# unit of force equivalent to the force generated by the effect of
# gravity
force = standard_free_fall = _ = forces

# unit of force, equal to the force that produces an acceleration of
# one centimeter per second per second on a mass of one gram (the
# standard centimeter-gram-second unit of force)
# [comment] exact
dyne = 1e-5 * N = _ = dynes

# unit of force, equal to the magnitude of the force exerted by one
# gram of mass in a 9.80665 m/s2 gravitational field
# [comment] exact
pond = 9.806650e-3 * N = _ = ponds

# unit of force, equal to the magnitude of the force exerted by one
# kilogram of mass in a 9.80665 m/s2 gravitational field
# [comment] exact
force_kilogram = 9.806650 * N = kgf = force_kilograms = kilogram_force = kilograms_force

# unit of force, equal to the magnitude of the force exerted by one
# ounce of mass in a 9.80665 m/s2 gravitational field
# [comment] exact
force_ounce = 2.780139e-1 * N = ozf = force_ounces = ounce_force = ounces_force

# unit of force, equal to the magnitude of the force exerted by one
# pound of mass in a 9.80665 m/s2 gravitational field
# [comment] exact
force_pound = 4.4482216152605 * N = lbf = force_pounds = pound_force = pounds_force

# unit of force, that which is necessary to accelerate 1 pound-mass to
# 1 foot per second per second
# [comment] exact
poundal = 1.382550e-1 * N = _ = poundals

# unit of force, equal to the magnitude of the force exerted by one
# gram of mass in a 9.80665 m/s2 gravitational field
# [comment] exact
gram_force = gram * force = gf = grams_force = force_gram = force_grams

# unit of force, equal to the magnitude of the force exerted by one
# ton of mass in a 9.80665 m/s2 gravitational field (specifically a
# short ton of mass)
# [comment] exact
force_ton = 2000 * force_pound = _ = force_tons = ton_force = tons_force

# unit of force, equal to the magnitude of the force exerted by one
# thousand pounds of mass in a 9.80665 m/s2 gravitational field
# [comment] exact
kip = 1000 * lbf = _ = kips

# unit of pressure, an international reference pressure intended to
# represent the mean atmospheric pressure at mean sea level at the
# latitude of Paris, France
# [comment] exact
standard_atmosphere = 1.01325e5 * Pa = atm = standard_atmospheres = atmosphere = atmospheres

# unit of pressure equal to one kilogram force per square centimeter
# [comment] exact; note that the symbol 'at' clashes with that of the
# katal ('kat'), the SI unit of catalytic activity
technical_atmosphere = 1 * kg * gravity / cm ** 2 = at = technical_atmospheres

# unit of pressure derived from pressure head calculations using
# metrology; represents the pressure exerted by a column of water of 1
# cm height at 4 degrees C
cm_H2O = cm * H2O = cmH2O

# unit of pressure representing the pressure exerted by a column of
# water of 1 inch height at 39 degrees F
# [comment] exact
inch_H2O_39F = inch * water_39F = _ = inches_H2O_39F

# unit of pressure representing the pressure exerted by a column of
# water of 1 inch height at 60 degrees F
# [comment] exact
inch_H2O_60F = inch * water_60F = _ = inches_H2O_60F

# unit of pressure representing the pressure exerted by a column of
# water of 1 foot height at 4 degrees C
foot_water = foot * water = ftH2O = feet_water = foot_H2O = feet_H2O = footH2O = feetH2O = fth2o

# unit of pressure representing the pressure exerted by a column of
# mercury of 1 cm height at 0 degrees C
cm_Hg = cm * Hg = cmHg

# unit of pressure representing the pressure exerted by a column of
# mercury of 1 mm height at 0 degrees C
# [comment] exact
millimeter_Hg_0C = mm * mercury_0C = _ = millimeters_Hg_0C

# unit of pressure representing the pressure exerted by a column of
# mercury of 1 inch height at 32 degrees F
# [comment] exact
inch_Hg_32F = inch * mercury_32F = _ = inches_Hg_32F

# unit of pressure representing the pressure exerted by a column of
# mercury of 1 inch height at 60 degrees F
# [comment] exact
inch_Hg_60F = inch * mercury_60F = _ = inches_Hg_60F

# unit of pressure representing the pressure exerted by a column of
# mercury of 1 mm height at 0 degrees C; approximately (within
# 0.000015%, generally below measurement error) 1 Torr, which is 1/760
# standard atmospheric pressure
millimeter_Hg = mm * Hg = mm_Hg = millimeters_Hg = torr = torrs = mm_hg = mmHg = mmhg

# unit of pressure representing the pressure exerted by a column of
# mercury of 1 inch height at 0 degrees C
inch_Hg = inch * Hg = in_Hg = inches_Hg = inHg

# unit of pressure representing the pressure exerted, due to gravity,
# by a one-pound mass, of area one square inch; commonly referred to
# as "pounds per square inch"
# [comment] exact
psi = 1 * pound * gravity / in ** 2

# unit of pressure representing the pressure exerted, due to gravity,
# by a 1000-pound mass, of area one square inch
# [comment] exact
ksi = kip / in ** 2

# unit of pressure equal to one dyne per square centimeter
# [comment] exact
barie = 0.1 * N / m ** 2 = _ = baries = barye = baryes

# logarithmic unit used to compare the sound pressure of an unknown
# sound to a standard reference sound pressure; is the base unit for
# "dB_SPL", a more typical logarithmic unit for measuring sound
# pressure (the SI unit for sound pressure is pascal); the standard
# reference sound pressure in air or other gases is 20 microPascal,
# which is usually considered the threshold of human hearing (at 1
# kHz)
# [comment] sound pressure level
B_SPL = 20e-6 * Pa; logbase: 10; logfactor: 10

# unit of dynamic viscosity, corresponding to 0.1 pascal-second
# (pascal-second: a fluid placed between two plates, when one plate is
# pushed sideways with a shear stress of one pascal, moves a distance
# equal to the thickness of the layer between the plates in one
# second)
# [comment] exact
poise = 1e-1 * Pa * s = _ = poises

# unit of kinematic viscosity, measuring the ratio of the dynamic
# viscosity to the density of the fluid; water at 20 degrees C has a
# kinematic viscosity about 100 stokes, or more cmomonly, 1 cSt
# [comment] exact
stokes = 1e-4 * m ** 2 / s = St = stokeses

# unit of fluidity (reciprocal of velocity), measured in reciprocal
# poise
# [comment] exact
rhe = 10 / (Pa * s) = _ = rhes

# unit of work, equal to the amount of work done by a force of one
# dyne exerted for a distance of one centimeter (in CGS base units,
# one gram centimeter-squared per second-squared)
# [comment] exact
erg = 1e-7 * J = _ = ergs

# unit of energy, equal to the energy needed to cool or heat one pound
# of water by one degree F; this uses the International Steam Table
# (IT) calorie , defined by the Fifth International Conference on the
# properties of Steam (1956)
# [comment] exact
IT_Btu = 1.05505585262e3 * J = _ = IT_Btus = Btu = Btus

# unit of energy legally defined by the Council Directive of 20
# December 1979, Council of the European Communities (now the European
# Union, EU);.roughly equal to 100,000 IT_Btu
# [comment] exact (reference NIST Guide to SI Units)
EC_therm = 1.05506e8 * J = _ = EC_therms

# unit of heat energy defined as 4.184 Joules exactly (International
# Standard ISO 31-4: Quantities and units, Part 4: Heat);
# approximately the energy needed to increase the temperature of 1
# gram of water by 1 C
# [comment] exact
thermochemical_calorie = 4.184000 * J = _ = thermochemical_calories

# unit of heat energy used in thermochemistry, the International Steam
# Table (IT) calorie defined by the Fifth International Conference on
# the properties of Steam (1956)
# [comment] exact
IT_calorie = 4.1868 * J = cal = IT_calories = calorie = calories

# unit of energy; approximately the energy released by the detonation
# of a given amount of mass of TNT
# [comment] by definition
TNT = 4.184 * MJ / kg = _

# unit of energy; approximately the energy released by the detonation
# of a 1000 kilograms of TNT
# [comment] by definition
ton_TNT = 4.184e9 * J = _ = tons_TNT

# unit of energy legally defined in the U.S. Federal Register of July
# 27, 1968, and the legal unit used by the U.S. natural gas industry
# [comment] exact
US_therm = 1.054804e8 * J = thm = US_therms = therm = therms

# unit of energy equal to the product of the power in watts and the
# time in hours (if the energy is being transmitted or used at a
# constant rate (power) over a period of time); one watt is equal to 1
# Joule/second
# [comment] exact
watthour = watt * hour = _ = watthours

# unit of energy corresponding to 1 billion electron volts (eV)
# [comment] exact
bev = 1e9 * eV

# unit of electric power equal to the product of one volt and one
# ampere, equivalent to one watt for direct current systems and a unit
# of apparent power for alternating current systems
# [comment] exact
voltampere = V * A = VA = voltamperes

# unit of power equal to the power required to evaporate 34.5 lb of
# fresh water at 212 degrees F in one hour; describes a boiler's
# capacity to deliver steam to a steam engine
boiler_horsepower = 9.80950e3 * W = _ = boiler_horsepowers

# unit of power originally corresponding to the estimated typical
# power of draft horses, calculated as lifting 33000 pounds one foot
# in one minute (550 foot-pounds/second)
# [comment] shaft_horsepower is a unit of power as delivered by a
# drive shaft at its output (e.g., of a ship, aircraft engine, or
# helicopter rotor; typically not automobiles due to drive train
# losses)
shaft_horsepower = 7.456999e2 * W = hp = shaft_horsepowers = horsepower = horsepowers

# unit of power corresponding to a calculation of 75 kilogram-
# meters/second
metric_horsepower = 7.35499e2 * W = _ = metric_horsepowers

# unit of power defined in the International System of Units as
# exactly 746 W; generally used for power used by electrical machines
# [comment] exact
electric_horsepower = 7.460000e2 * W = _ = electric_horsepowers

# unit of power used in the U.S. primarily in rating pumps; calculated
# as pump capacity Q (gallons per minute) times pump pressure ("head")
# of P (feet of head), divided by 3956 water horsepower; the
# calculation assumes water density is 8 1/3 pounds per U.S. gallon,
# which is not exact.
water_horsepower = 7.46043e2 * W = _ = water_horsepowers

# unit of power originally corresponding to the estimated typical
# power of draft horses, calculated as lifting 33000 pounds one foot
# in one minute (550 foot-pounds/second), as calculated/specified in
# the United Kingdom
UK_horsepower = 7.4570e2 * W = _ = UK_horsepowers

# unit of power describing the heat-extraction capacity of cooling
# equipment; defined as the heat absorbed by melting 1 short ton of
# pure ice at 0 degrees C in 24 hours
refrigeration_ton = 12000 * Btu / hr = _ = refrigeration_tons = ton_of_refrigeration = tons_of_refrigeration

# unit of power in decibel scale, referenced to 1 watt; the power in
# bel-watts is equal to 100 times the base 10 logarithm of the power
# in watts (making decibel-watt, the more common term, 10 times the
# base 10 log of the power in watts)
BW = 1 * W; logbase: 10; logfactor: 10

# unit of power in decibel scale, referenced to 1 milliwatt; the power
# in bel-milliwatts is equal to 100 times the base 10 logarithm of the
# power in milliwatts (making decibel-milliwatt, the more common term,
# 10 times the base 10 log of the power in milliwatts)
Bm = 1 * mW; logbase: 10; logfactor: 10

# unit of thermal resistance used in describing the insulating value
# of clothing; the amount of thermal resistance needed to maintain in
# comfort a resting subject in a normally ventilated room (air
# movement 10 cm/sec) at a temperature of 20 degrees C and a humidity
# less than 50%
clo = 1.55e-1 * K * m ** 2 / W = _ = clos

# basic unit of electricity in the electromagnetic CGS system of units
abampere = 10 * A = _ = abamperes

# unit of electricity/magnetism
gilbert = 7.957747e-1 * A = _ = gilberts

# unit of electricity/magnetism
statampere = 3.335640e-10 * A = _ = statamperes

# basic unit of electricity in the electromagnetic CGS system of units
# (same as abampere), named after Jean-Baptiste Biot
biot = 10 * A = _ = biots

# unit of electricity/magnetism
# [comment] exact
abfarad = 1e9 * F = _ = abfarads

# unit of electricity/magnetism
# [comment] exact
abhenry = 1e-9 * H = _ = abhenries

# unit of electricity/magnetism
# [comment] exact
abmho = 1e9 * S = _ = abmhos

# unit of electricity/magnetism
# [comment] exact
abohm = 1e-9 * ohm = _ = abohms

# unit of electricity/magnetism
# [comment] exact
abvolt = 1e-8 * V = _ = abvolts

# unit of electricity/magnetism
e = 1.602176487e-19 * C

# unit of electricity/magnetism
chemical_faraday = 9.64957e4 * C = _ = chemical_faradays

# unit of electricity/magnetism
physical_faraday = 9.65219e4 * C = _ = physical_faradays

# unit of electricity/magnetism
C12_faraday = 9.648531e4 * C = _ = C12_faradays = faraday = faradays

# unit of electricity/magnetism
# [comment] exact
gamma = 1e-9 * T = _ = gammas

# unit of electricity/magnetism
# [comment] exact
gauss = 1e-4 * T = _ = gausses

# unit of electricity/magnetism
# [comment] exact
maxwell = 1e-8 * Wb = _ = maxwells

# unit of electricity/magnetism
oersted = 7.957747e1 * A / m = Oe = oersteds

# unit of electricity/magnetism
statcoulomb = 3.335640e-10 * C = _ = statcoulombs

# unit of electricity/magnetism
statfarad = 1.112650e-12 * F = _ = statfarads

# unit of electricity/magnetism
stathenry = 8.987554e11 * H = _ = stathenries

# unit of electricity/magnetism
statmho = 1.112650e-12 * S = _ = statmhos

# unit of electricity/magnetism
statohm = 8.987554e11 * ohm = _ = statohms

# unit of electricity/magnetism
statvolt = 2.997925e2 * V = _ = statvolts

# unit of electricity/magnetism
unit_pole = 1.256637e-7 * Wb = _ = unit_poles

# unit of electricity/magnetism
BV = 1 * V; logbase: 10; logfactor: 10

# unit of electricity/magnetism
# [comment] rms voltage
Bv = 0.775 * V; logbase: 10; logfactor: 10

# unit of electricity/magnetism
# [comment @ BµV] uses MICRO SIGN
BµV = 1e-6 * V; logbase: 10; logfactor: 10

# unit of thermodynamic temperature
# [comment @ °R] DEGREE SIGN
degree_rankine = K / 1.8 = °R = degrees_rankine = degreeR = degreesR = degree_R = degrees_R = degR = degsR = deg_R = degs_R

# unit of thermodynamic temperature
# [comment @ °F] DEGREE SIGN
# [comment @ ℉] DEGREE FAHRENHEIT
fahrenheit = °R; offset: 459.67 = °F = fahrenheits = ℉ = degree_fahrenheit = degrees_fahrenheit = degreeF = degreesF = degree_F = degrees_F = degF = degsF = deg_F = degs_F

# unit of illumination
footcandle = 1.076391e-1 * lx = _ = footcandles

# unit of illumination
# [comment] exact
footlambert = 3.426259 * cd / m ** 2 = _ = footlamberts

# unit of illumination
# [comment] exact
lambert = (1e4 / pi) * cd / m ** 2 = _ = lamberts

# unit of illumination
# [comment] exact
stilb = 1e4 * cd / m ** 2 = sb = stilbs

# unit of illumination
# [comment] exact
phot = 1e4 * lm / m ** 2 = ph = phots

# unit of illumination
# [comment] exact
nit = 1 * cd / m ** 2 = nt = nits

# unit of illumination
# [comment] exact
langley = 4.184000e4 * J / m ** 2 = _ = langleys

# unit of illumination
# [comment] exact
blondel = cd / (pi * m ** 2) = _ = blondels = apostilb = apostilbs

# [comment] exact
kayser = 100 / m = _ = kaysers

# [comment] exact
geopotential = gravity = gp = geopotentials = dynamic = dynamics

# [comment] exact
work_year = 2056 * hours = _ = work_years

# [comment] exact
work_month = work_year / 12 = _ = work_months

# [comment] exact
potential_vorticity_unit = 1e-6 * m ** 2 * s ** -1 * K * kg ** -1 = PVU = potential_vorticity_units

count = 1 = _ = counts

bit = 1 = _ = bits

octet = 8 = _ = octets = byte = bytes

dobson = 446.2 * micromoles / meter ** 2 = DU = dobsons

molecule = 1 / avogadro_constant = _ = molecules = molec = molecs = nucleon = nucleons = nuc = nucs
