IfcIonConcentrationMeasure inconsistency

[CBenghi]

The unit for IfcIonConcentrationMeasure has changed in IFC4x3 from mg/L to mol/m3.

Cfr.
https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcIonConcentrationMeasure.htm

In IFC this is not a problem because derived units characterise the unit fully, but we need to be aware of such difference in IDS.

IDS/Documentation/UserManual/units.md

Line 35 in 016bbad

| IFCIONCONCENTRATIONMEASURE | Ion concentration measure | | | mol / m3 | (-3, 1, 0, 0, 0, 0, 0) | IfcDerivedUnitEnum.IONCONCENTRATIONUNIT | |

How do we want to fix this?

• I suppose that we should fix the inconsistent exponent mol/m3 does not match (-3, 1, 0, 0, 0, 0, 0), it should be (-3, 0, 0, 0, 0, 1, 0)
• Should we also document the change and provide a warning?
• Do we need to add an auditing tool constraint to prevent value specifications on such measure if applied across [4x3] and [2x3,4]?
• perhaps add a column to the table to identify the relevant schemas and duplicate the line with the two units.