IfcConversionBasedUnitWithOffset is a unit which is converted from another unit by applying a conversion factor and an offset.
HISTORY New entity in IFC4.
Example: The temperature unit Fahrenheit is based on the temperature unit Kelvin as follows:
f = k · 1.8 – 459.67
wherein k is an absolute temperature expressed in Kelvin and f is the same temperature in Fahrenheit. The following entity instances provide Fahrenheit as a unit:
IfcDimensionalExponents(0, 0, 0, 0, 1, 0, 0),
IfcSIUnit(THERMODYNAMICTEMPERATUREUNIT, ?, KELVIN)),
|1||Dimensions||IfcDimensionalExponents||The dimensional exponents of the SI base units by which the named unit is defined.|
|2||UnitType||IfcUnitEnum||The type of the unit.|
|3||Name||IfcLabel||The word, or group of words, by which the conversion based unit is referred to.|
|4||ConversionFactor||IfcMeasureWithUnit||The physical quantity from which the converted unit is derived.|
|HasExternalReference||SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects||Reference to external information, e.g. library, classification, or document information, which is associated with the conversion-based unit.|
> IFC4 CHANGE New inverse attribute.
|5||ConversionOffset||IfcReal||A positive or negative offset to add after the inherited ConversionFactor was applied.|
ENTITY IfcConversionBasedUnitWithOffset SUBTYPE OF (IfcConversionBasedUnit); ConversionOffset : IfcReal; END_ENTITY;