IfcConversionBasedUnitWithOffset

BACnet MVD

#### IfcConversionBasedUnitWithOffset

Natural language names

| Auf Umrechnung basierte Einheit mit Abzug
| Conversion Based Unit With Offset
| Unité basée sur une mesure avec unité et avec décalage

Change log

Item | SPF | XML | Change | Description
--- | --- | --- | --- | ---
IFC2x3 to IFC4
IfcConversionBasedUnitWithOffset |  |  | ADDED |

##### Semantic definitions at the entity

Entity definition

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:

> `IfcConversionBasedUnitWithOffset(
> IfcDimensionalExponents(0, 0, 0, 0, 1, 0, 0),
> THERMODYNAMICTEMPERATUREUNIT,
> 'Fahrenheit',
> IfcMeasureWithUnit(
> IfcThermodynamicTemperatureMeasure(1.8),
> IfcSiUnit(THERMODYNAMICTEMPERATUREUNIT, ?, KELVIN)),
> -459.67);`

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
5 | ConversionOffset | IfcReal |  | A positive or negative offset to add after the inherited ConversionFactor was applied. |  | X

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcNamedUnit
1 | Dimensions | IfcDimensionalExponents |  | The dimensional exponents of the SI base units by which the named unit is defined. |  | X
2 | UnitType | IfcUnitEnum |  | The type of the unit. |  | X
IfcConversionBasedUnit
3 | Name | IfcLabel |  | The word, or group of words, by which the conversion based unit is referred to. |  | X
4 | ConversionFactor | IfcMeasureWithUnit |  | The physical quantity from which the converted unit is derived. |  | X

HasExternalReference

IfcExternalReferenceRelationship
@RelatedResourceObjects

S[0:?]

Reference to external information, e.g. library, classification, or document information, which is associated with the conversion-based unit.

> IFC4 CHANGE New inverse attribute.

X

IfcConversionBasedUnitWithOffset
5 | ConversionOffset | IfcReal |  | A positive or negative offset to add after the inherited ConversionFactor was applied. |  | X

##### Formal representations

XML Specification
`<xs:element name="IfcConversionBasedUnitWithOffset" type="ifc:IfcConversionBasedUnitWithOffset" substitutionGroup="ifc:IfcConversionBasedUnit" nillable="true"/>
<xs:complexType name="IfcConversionBasedUnitWithOffset">
<xs:complexContent>
<xs:extension base="ifc:IfcConversionBasedUnit">
<xs:attribute name="ConversionOffset" type="ifc:IfcReal" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcConversionBasedUnitWithOffset
SUBTYPE OF (IfcConversionBasedUnit);
ConversionOffset : IfcReal;
END_ENTITY;

EXPRESS-G diagram

`

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