The Measurement Ontology is an ontology in which measurements may be rendered.
A measurement is a statistic that measures a quantity that may or may not have units.
Measurement
A quantity is a quantifiable quality of an object.
Quantity
A unit is a particular quantity against which another quantity may be compared. Hence, a unit is dimensionful and provides a ratio by which a quantity may be measured.
Unit
A unit class is a subset of units, with no particular restriction on its contents (i.e. it may be a set of units measuring orthogonal quantities, making a UnitSystem, or a set of units measuring the same quantity).
Unit Class
A unit system is a class of units for which no two elements in the class measure the same dimension (i.e. all dimensions are orthogonal to each other, or measure dimensions derived from a set of orthogonal dimensions with units derived from the units that measure those orthogonal dimensions specified in the system.
Unit System
An equivalent unit class of a quantity is the unit class corresponding to units that measure the quantity.
equivalent unit class
An equivalent quantity of a unit class is the quantity measured by all units in the unit class.
equivalent quantity
The quantity measured for a measurement.
measured quantity
The unit a measurement is made in.
unit
Area
Area Unit
square kilometers
Area Measurement
area