---
_meta:
  source: unitsdb v2.0.0
  source_path: https://github.com/unitsml/unitsdb
  note: |-
    All units, prefixes, and quantities are referenced by their unitsml ID
    (u:meter, p:milli, q:length). These are ASCII, unambiguous, and
    cross-reference https://github.com/unitsml/unitsdb.

    Surface symbols (V, Ω, m) are display hints rendered at view time,
    never stored in cert data. Renderers look up the symbol via unit_id.

    Closed enum: any unit/prefix/quantity not in this file is invalid.
quantities:
  description: Physical quantities from unitsdb/quantities.yaml
  enum:
  - q:length
  - q:volume
  - q:diameter
  - q:length_of_path
  - q:cartesian_coordinates
  - q:position_vector
  - q:displacement
  - q:radius_of_curvature
  - q:curvature
  - q:speed_of_propagation_of_waves
  - q:acceleration_of_free_fall
  - q:period_duration
  - q:solid_angle
  - q:time_constant
  - q:rotation
  - q:rotational_frequency
  - q:angular_frequency
  - q:wavelength
  - q:angular_wavenumber
  - q:phase_velocity
  - q:group_velocity
  - q:level_of_a_field_quantity
  - q:level_of_a_power_quantity
  - q:velocity
  - q:damping_coefficient
  - q:logarithmic_decrement
  - q:attenuation_coefficient
  - q:phase_coefficient
  - q:propagation_coefficient
  - q:relative_mass_density
  - q:linear_density
  - q:mass_moment_of_inertia
  - q:weight
  - q:impulse
  - q:force
  - q:gravitational_constant
  - q:momentum
  - q:moment_of_momentum
  - q:angular_impulse
  - q:normal_stress
  - q:shear_stress
  - q:linear_strain
  - q:shear_strain
  - q:volume_strain
  - q:compressibility
  - q:magnetic_flux_density
  - q:poisson_number
  - q:modulus_of_elasticity
  - q:modulus_of_rigidity
  - q:modulus_of_compression
  - q:second_axial_moment_of_area
  - q:second_polar_moment_of_area
  - q:section_modulus
  - q:dynamic_friction_factor
  - q:pressure
  - q:mass_flow_rate
  - q:volume_flow_rate
  - q:lagrange_function
  - q:hamilton_function
  - q:action
  - q:area_moment_of_inertia
  - q:linear_expansion_coefficient
  - q:cubic_expansion_coefficient
  - q:relative_pressure_coefficient
  - q:pressure_coefficient
  - q:stress
  - q:isothermal_compressibility
  - q:magnetomotive_force
  - q:electric_dipole_moment
  - q:magnetizability
  - q:magnetic_dipole_moment
  - q:electric_field_gradient
  - q:electric_potential
  - q:electric_quadrupole_moment
  - q:polarizability
  - q:electric_capacitance
  - q:energy
  - q:electric_current_intensity
  - q:electric_inductance
  - q:first_hyperpolarizability
  - q:second_hyperpolarizability
  - q:index_of_acidity
  - q:fahrenheit_temperature
  - q:mass_divided_by_length
  - q:storage_capacity
  - q:molality_of_solute_B
  - q:work
  - q:coefficient_of_heat_transfer
  - q:surface_coefficient_of_heat_transfer
  - q:kinetic_energy
  - q:mechanical_energy
  - q:torque
  - q:bending_moment_of_force
  - q:mass_fraction
  - q:apparent_power
  - q:nil
  - q:emission_rate
  - q:amount_of_heat
  - q:fluence
  - q:fluence_rate
  - q:ITS-90_temperature_celsius
  - q:ITS-90_temperature_kelvin
  - q:kerma_rate
  - q:phase
  - q:PLTS-2000_temperature
  - q:exposure
  - q:fuel_efficiency
  - q:relative_humidity
  - q:mass
  - q:power
  - q:logarithmic_frequency_range
  - q:traffic_intensity
  - q:symbol_rate
  - q:information_content
  - q:radiant_flux
  - q:electric_charge
  - q:amount_of_electricity
  - q:electric_potential_difference
  - q:potential_difference
  - q:electromotive_force
  - q:capacitance
  - q:electric_resistance
  - q:electric_conductance
  - q:time
  - q:magnetic_flux
  - q:surface_density
  - q:inductance
  - q:mass_concentration
  - q:celsius_temperature
  - q:activity_referred_to_a_radionuclide
  - q:absorbed_dose
  - q:specific_energy_imparted
  - q:kerma
  - q:dose_equivalent
  - q:electric_current
  - q:ambient_dose_equivalent
  - q:directional_dose_equivalent
  - q:personal_dose_equivalent
  - q:organ_dose_equivalent
  - q:catalytic_activity
  - q:frequency
  - q:luminous_flux
  - q:illuminance
  - q:distance
  - q:acceleration
  - q:temperature
  - q:wavenumber
  - q:density
  - q:specific_volume
  - q:current_density
  - q:magnetic_field_strength
  - q:amount_concentration
  - q:luminance
  - q:angular_velocity
  - q:angular_acceleration
  - q:dynamic_viscosity
  - q:substance_amount
  - q:moment_of_force
  - q:surface_tension
  - q:heat_flux_density
  - q:heat_capacity
  - q:specific_heat_capacity
  - q:specific_energy
  - q:thermal_conductivity
  - q:energy_density
  - q:electric_field_strength
  - q:electric_charge_density
  - q:luminous_intensity
  - q:electric_flux_density
  - q:permittivity
  - q:permeability
  - q:molar_energy
  - q:molar_entropy
  - q:exposure_x_and_gamma_rays
  - q:absorbed_dose_rate
  - q:potential_energy
  - q:irradiance
  - q:entropy
  - q:area
  - q:specific_entropy
  - q:surface_charge_density
  - q:electric_displacement
  - q:molar_heat_capacity
  - q:catalytic_activity_concentration
  - q:kinematic_viscosity
  - q:magnetic_field
  - q:radiant_intensity
  - q:radiance
  - q:plane_angle
  - q:logarithmic_ratio_quantities
  - q:fluidity
  - q:hydrodynamic_permeability
  - q:refractive_index
  - q:relative_permeability
  - q:breadth
  - q:height
  - q:thickness
  - q:radius
  - q:radial_distance
prefixes:
  description: SI prefixes from unitsdb/prefixes.yaml. Use unitsml id (p:milli), never unicode symbol.
  enum:
  - p:yobi
  - p:zebi
  - p:exbi
  - p:pebi
  - p:tebi
  - p:gibi
  - p:quetta
  - p:ronna
  - p:yotta
  - p:zetta
  - p:mebi
  - p:exa
  - p:peta
  - p:tera
  - p:kibi
  - p:giga
  - p:mega
  - p:kilo
  - p:hecto
  - p:deka
  - p:none
  - p:deci
  - p:centi
  - p:milli
  - p:micro
  - p:nano
  - p:pico
  - p:femto
  - p:atto
  - p:zepto
  - p:yocto
  - p:ronto
  - p:quecto
units:
  description: Canonical units from unitsdb/units.yaml. Use unitsml id (u:meter).
  enum:
  - u:meter
  - u:meter_per_second
  - u:meter_per_second_squared
  - u:steradian
  - u:rem
  - u:year_365
  - u:foot_per_minute
  - u:foot_per_second
  - u:inch_per_second
  - u:newton
  - u:newton_meter
  - u:newton_meter_second
  - u:newton_per_meter
  - u:newton_meter_squared_per_kilogram_squared
  - u:newton_second
  - u:mile_per_hour
  - u:mile_per_minute
  - u:mile_per_second
  - u:stere
  - u:gamma
  - u:ec_therm
  - u:roentgen
  - u:gauss
  - u:pascal
  - u:pascal_second
  - u:pascal_per_kelvin
  - u:kayser
  - u:centistokes
  - u:micron
  - u:mil (length)
  - u:stilb
  - u:kilogram_force_second_squared_per_meter
  - u:kilogram_force_meter
  - u:electric_horsepower
  - u:poise
  - u:rhe
  - u:pascal_to_the_power_minus_one
  - u:joule
  - u:joule_per_cubic_meter
  - u:joule_per_kilogram
  - u:joule_per_kilogram_kelvin
  - u:joule_second
  - u:joule_per_kelvin
  - u:joule_per_mole
  - u:joule_per_mole_kelvin
  - u:liter
  - u:nautical_mile
  - u:degree_Fahrenheit
  - u:standard_atmosphere
  - u:technical_atmosphere
  - u:watt
  - u:watt_per_steradian
  - u:watt_per_meter_kelvin
  - u:watt_per_square_meter
  - u:watt_per_square_meter_steradian
  - u:watt_second
  - u:stokes
  - u:gal
  - u:oersted
  - u:arc_minute
  - u:arc_second
  - u:arc_degree
  - u:coulomb
  - u:coulomb_per_square_meter
  - u:coulomb_per_cubic_meter
  - u:coulomb_per_kilogram
  - u:knot
  - u:neper
  - u:bel
  - u:decibel
  - u:mm_Hg
  - u:darcy
  - u:gon
  - u:volt
  - u:volt_per_meter
  - u:kilometer_per_hour
  - u:neper_per_second
  - u:square_yard
  - u:square_mile
  - u:tons_of_tnt
  - u:foot_per_second_squared
  - u:cubic_inch
  - u:cubic_foot
  - u:farad
  - u:farad_per_meter
  - u:cubic_yard
  - u:imperial_gallon
  - u:imperial_pint
  - u:imperial_ounce
  - u:us_gallon
  - u:us_pint
  - u:us_fluid_ounce
  - u:petro_barrel
  - u:us_bushel
  - u:ohm
  - u:us_dry_pint
  - u:light_year
  - u:astronomical_unit
  - u:parsec
  - u:meter_to_the_power_four
  - u:kilogram_per_liter
  - u:metric_ton_per_cubic_meter
  - u:siemens
  - u:gram_force
  - u:meter_to_the_power_minus_one
  - u:meter_to_the_power_minus_two
  - u:meter_to_the_power_minus_two_per_second
  - u:square_meter
  - u:meter_squared_per_second
  - u:cubic_meter
  - u:cubic_meter_per_kilogram
  - u:cubic_meter_per_second
  - u:kilogram
  - u:weber
  - u:av_pound
  - u:av_ounce
  - u:gross_hundredweight
  - u:pound_per_cubic_foot
  - u:pound_force
  - u:foot_pound_force
  - u:pound_force_per_square_inch
  - u:inch_to_the_fourth_power
  - u:inch_cubed
  - u:tesla
  - u:foot_squared_per_second
  - u:foot_pound_force_per_second
  - u:carat
  - u:tex
  - u:torr
  - u:mm_water
  - u:thermo_btu
  - u:kilogram_force_meter_per_second
  - u:metric_horsepower
  - u:henry
  - u:henry_per_meter
  - u:watt_per_square_meter_kelvin
  - u:lambert
  - u:gilbert
  - u:debye
  - u:abwatt
  - u:slug
  - u:thermo_calorie
  - u:short_ton
  - u:long_ton
  - u:degree_Celsius
  - u:hundredweight
  - u:troy_ounce
  - u:troy_pound
  - u:pennyweight
  - u:apothecaries_dram
  - u:scruple
  - u:poundal
  - u:kip
  - u:ton_force
  - u:barye
  - u:electronvolt
  - u:unified_atomic_mass_unit
  - u:natural_unit_of_velocity
  - u:natural_unit_of_action
  - u:natural_unit_of_mass
  - u:natural_unit_of_time
  - u:atomic_unit_of_charge
  - u:atomic_unit_of_mass
  - u:atomic_unit_of_action
  - u:atomic_unit_of_length
  - u:becquerel
  - u:atomic_unit_of_energy
  - u:atomic_unit_of_time
  - u:atomic_unit_of_magnetizability
  - u:atomic_unit_of_magnetic_flux_density
  - u:atomic_unit_of_magnetic_dipole_moment
  - u:atomic_unit_of_momentum
  - u:atomic_unit_of_charge_density
  - u:atomic_unit_of_current
  - u:atomic_unit_of_electric_dipole_moment
  - u:atomic_unit_of_electric_field
  - u:fermi
  - u:atomic_unit_of_electric_field_gradient
  - u:atomic_unit_of_electric_potential
  - u:atomic_unit_of_force
  - u:atomic_unit_of_electric_quadrupole_moment
  - u:atomic_unit_of_electric_polarizability
  - u:statohm
  - u:statfarad
  - u:statampere
  - u:statvolt
  - u:stathenry
  - u:gram
  - u:statmho
  - u:statcoulomb
  - u:statweber
  - u:stattesla
  - u:statwatt
  - u:av_dram
  - u:footcandle
  - u:footlambert
  - u:computer_pica
  - u:printers_pica
  - u:kilogram_meter_per_second
  - u:kilogram_per_meter
  - u:kilogram_per_square_meter
  - u:kilogram_per_cubic_meter
  - u:kilogram_meter_squared
  - u:kilogram_meter_squared_per_second
  - u:kilogram_per_second
  - u:gray
  - u:gray_per_second
  - u:computer_point
  - u:us_survey_rod
  - u:us_survey_fathom
  - u:circular_mil
  - u:horsepower
  - u:boiler_horsepower
  - u:water_horsepower
  - u:uk_horsepower
  - u:degree_Rankine
  - u:dalton
  - u:sievert
  - u:natural_unit_of_length
  - u:atomic_unit_of_1st_hyperpolarizability
  - u:atomic_unit_of_2nd_hyperpolarizability
  - u:atomic_unit_of_permittivity
  - u:atomic_unit_of_velocity
  - u:natural_unit_of_energy
  - u:natural_unit_of_momentum
  - u:natural_unit_of_action_in_eV_s
  - u:natural_unit_of_energy_in_MeV
  - u:natural_unit_of_momentum_in_MeV_per_c
  - u:second
  - u:katal
  - u:katal_per_cubic_meter
  - u:imperial_quart
  - u:us_dry_quart
  - u:us_quart
  - u:us_teaspoon
  - u:us_tablespoon
  - u:us_label_tablespoon
  - u:us_label_teaspoon
  - u:us_label_cup
  - u:us_label_fluid_ounce
  - u:us_label_ounce
  - u:hertz
  - u:us_survey_chain
  - u:us_survey_link
  - u:us_survey_furlong
  - u:us_survey_mile
  - u:us_survey_yard
  - u:us_survey_foot
  - u:us_survey_inch
  - u:us_acre
  - u:cm_Hg
  - u:0C_cm_Hg
  - u:lumen
  - u:4C_cm_water
  - u:cm_water
  - u:in_water
  - u:39F_in_water
  - u:60F_in_water
  - u:ft_water
  - u:39F_ft_water
  - u:32F_in_Hg
  - u:60F_in_Hg
  - u:in_Hg
  - u:lux
  - u:ft_Hg
  - u:us_therm
  - u:pH
  - u:table_btu
  - u:mean_btu
  - u:39F_btu
  - u:59F_btu
  - u:60F_btu
  - u:tropical_year
  - u:sidereal_year
  - u:sidereal_day
  - u:sidereal_hour
  - u:sidereal_minute
  - u:sidereal_second
  - u:printers_point
  - u:shake
  - u:denier
  - u:nato_mil
  - u:pound_mole
  - u:ton_refrigeration
  - u:bit
  - u:byte
  - u:us_peck
  - u:us_minim
  - u:us_cup
  - u:us_fluid_dram
  - u:us_gill
  - u:imperial_gill
  - u:cubic_foot_per_minute
  - u:cubic_foot_per_second
  - u:minute
  - u:cubic_inch_per_minute
  - u:microinch
  - u:millibar
  - u:mile_per_gallon
  - u:gallon_per_minute
  - u:milliliter
  - u:mole_per_liter
  - u:hour
  - u:light_week
  - u:light_hour
  - u:light_minute
  - u:light_second
  - u:day
  - u:kilometer_per_liter
  - u:decibel_milliwatt
  - u:relative_humidity
  - u:octave
  - u:decade
  - u:erlang
  - u:baud
  - u:shannon
  - u:hartley
  - u:angstrom
  - u:second_to_the_power_minus_one
  - u:ampere
  - u:ampere_per_meter
  - u:ampere_per_square_meter
  - u:parts_per_million
  - u:var
  - u:are
  - u:barn
  - u:hectare
  - u:square_foot
  - u:square_inch
  - u:abampere
  - u:abcoulomb
  - u:abfarad
  - u:kelvin
  - u:abhenry
  - u:abmho
  - u:abohm
  - u:abvolt
  - u:ampere_hour
  - u:biot
  - u:us_survey_acre_foot
  - u:maxwell
  - u:kelvin_to_the_power_minus_one
  - u:mole
  - u:mole_per_cubic_meter
  - u:mole_per_kilogram
  - u:table_calorie
  - u:one
  - u:erg
  - u:table_kg_calorie
  - u:thermo_kg_calorie
  - u:kilowatt_hour
  - u:watt_hour
  - u:candela
  - u:candela_per_square_meter
  - u:dyne
  - u:kilogram_force
  - u:kilopond
  - u:calorie_th_per_second
  - u:kilocalorie_th_per_second
  - u:foot
  - u:inch
  - u:mile
  - u:yard
  - u:phot
  - u:grain
  - u:metric_ton
  - u:erg_per_second
  - u:radian
  - u:radian_per_meter
  - u:radian_per_second
  - u:radian_per_second_squared
  - u:bar
  - u:dyne_per_square_centimeter
  - u:gram_force_per_square_centimeter
  - u:kilogram_force_per_square_centimeter
  - u:kilogram_force_per_square_meter
  - u:kilogram_force_per_square_millimeter
  - u:centipoise
  - u:curie
  - u:rad

definitions:
  Unit:
    description: |
      Structured unit reference. Composed of a unitsml unit_id (closed enum
      from unitsdb/units.yaml), an optional SI prefix (closed enum from
      unitsdb/prefixes.yaml), and optional application qualifiers
      (current_type, pressure_reference) that are not unitsdb concepts.
    type: object
    properties:
      unit_id:
        description: Canonical unitsml unit identifier (e.g. u:meter, u:volt).
        enum_file: _units.yaml
        enum: []  # populated at load time from the top-level units.enum above
      prefix:
        description: SI prefix from unitsdb/prefixes.yaml (e.g. p:milli). Null if none.
        type: [string, "null"]
      current_type:
        description: Electrical current qualifier — for AC vs DC of voltage/ampere units.
        type: [string, "null"]
        enum: [AC, DC, null]
      pressure_reference:
        description: Pressure reference qualifier — gauge / absolute / differential.
        type: [string, "null"]
        enum: [gauge, absolute, differential, null]
    additionalProperties: false

  Quantity:
    description: Physical quantity from unitsdb/quantities.yaml.
    type: object
    properties:
      quantity_id:
        description: Canonical unitsml quantity identifier (e.g. q:length).
        type: string
      dimension_id:
        description: Reference to a unitsml dimension (e.g. NISTd1).
        type: string
    additionalProperties: false