|
Type |
Ontology |
|
Coverage |
Limited / around 1750 Units originating from 10 systems of units for 880 quantity kinds |
|
Hosted by |
public charity non-profit organization |
|
Homepage |
The QUDT ontology includes
- physical constants, quantity kinds, units, unit systems, prefixes and dimension vectors
- a semantic description of the named entries including the relation to other entries
- translations to other standards of unit description
QUDT is modelled in OWL (Web Ontology Language). Other descriptions and interfaces are available like RDF/XML, TURTLE, JSON or SPARQL.
QUDT not only focuses on defining models and a publicly available vocabulary to express quantities and units but also wants to offer a translation between existing standards doing the same. Therefore, the ontology also names UCUM, UNECE, IEC 61360 and LaTeX codes for the entries.
QUDT originated from a NASA project trying to define a semantic specification for units of measure, quantity kind and dimensions used in science and engineering. Today it is governed by a board of directors from different research institutes and the industry.
Quantity examples:
|
QUDT code |
Symbol |
Name |
|
quantitykind:Length |
l |
length |
|
quantitykind:LinearThermalExpansion |
m/K |
linear thermal expansion |
Unit examples:
|
QUDT code |
Symbol |
Name |
|
unit:M |
m |
metre |
|
unit:CentiM |
cm |
centimetre |
|
unit:MI_N |
n mile |
nautical mile |
|
unit:ANGSTROM |
Å |
angstrom |
|
unit:MicroM-PER-K |
µm/K |
micrometre per kelvin |
|
unit:FATH |
fath |
fathom |