IfcPhysicalQuantity

IfcPhysicalQuantity

Definition from IAI: The physical quantity, IfcPhysicalQuantity, is an entity that holds a quantiy measure value (as defined at the subtypes of IfcPhysicalQuantity) together with a semantic definition of the usage for the measure value.

EXAMPLE: An element, like a wall, may have several area measures, like footprint area, left wall face area, right wall face area. These areas would be given by three instances of the area quantity subtype, with different Name string values.

The Name attribute defines the actual usage or kind of measure. The interpretation of the name label has to be established within the actual exchange context. In addition an informative text may be associated to each quantity.

HISTORY New entity in IFC Release 2.x.
NOTE: It replaces the calcXxx attributes used in previous IFC Releases
ISSUE See issue and change log for changes made in IFC Release 2.x

EXPRESS specification:

ENTITY IfcPhysicalQuantity

ABSTRACT SUPERTYPE OF

(ONEOF(IfcQuantityLength, IfcQuantityArea, IfcQuantityVolume, IfcQuantityCount, IfcQuantityWeight));

Name

IfcLabel;

Description

OPTIONAL IfcText;

Unit

OPTIONAL IfcNamedUnit;

END_ENTITY;

Attribute definitions:

Name	:	Name of the element quantity or measure. The name attribute has to be made recognizable by further agreements.
Description	:	Further explanation that might be given to the quantity.
Unit	:	Optional assignment of a unit. If no unit is given, than the global unit assignment, as established at the IfcProject, applies to the quantity measures.