How to describe the target Unit for phys_unit:conversionFactor?

[changqin26]

Hello,

in the AAS Data Specification Physical Unit, we have the attribute - conversionFactor. The screenshot is the example from the Specification, where the unit "1/min" has a conversion factor 1.0/60. However, the target/output unit after applying this conversion factor is not indicated within this template. In other words, how should we express the actual meaning of this conversion factor?

[CerealZ]

Hi, perhaps I can further describe that question from @changqin26 with an example (for spec 3.0.RC01)

Let's say we have some proprietary property with a custom unit. For argument's sake let's use dA = deciAmpere. We first describe the property in a DataSpecificationIEC61360 and then link a DataSpecificationPhysicalUnit via unitId. That physical unit describes what a 'dA' is and assigns a conversion factor of '10' to get to A.

As a human I can infer that the result of that conversion is Ampere, but a machine can't. That explicit assignment is missing in this case. Or perhaps I interpret the usage wrong?

[changqin26]

Hello @BirgitBoss, may you have a clue to this question?

[BirgitBoss]

I am not really an expert on physical unit and its conversions. Probably the confusion arises from the fact that one additionally needed data specification for quantities is not (yet) offered to completely describe the semantics of a physical unit. In the example you need to refer to the ECLASS dictionary and Wiki for this missing information.

[changqin26]

Thanks for the hint, our customer has a clue to solve it now. We can close this issue.

[StenGruener]

@changqin26 any insights you could share?

[changqin26]

@StenGruener A new attribute of Physical Unit called "targetUnit" will be added and point to the IRDI of the target unit in Eclass or in CDD.