[Bug?]: Validation emits warning for specific unit even though NeXus Unit Category is NX_ANY

[mkuehbach]

Contact Details

No response

What happened?

The concept power_setting of NXelectromagnetic_lens has NeXus Unit Category NX_ANY
The concept docstring states

Descriptor for the lens excitation when the exact technical details are unknown
or not directly controllable as the control software of the microscope does not
enable or was not configured to display these values for users.

So the data entered can be of NX_UNITLESS, NX_DIMENSIONLESS, percent, or some specific engineering quantities.
The NeXus documentations states that NX_ANY is for case where one is not "picky about the unit"
Given that the concept is of NX_CHAR_OR_NX_NUMBER one could even state, "fully cranked up"

However, still though the validator emits a warning where it should not.

Relevant log output

WARNING: The unit '%' at /ENTRY[entry1]/measurement/eventID[event4]/instrument/ebeam_column/lensID[lens6]/power_setting/@units does not match with the unit category NX_ANY of 'power_setting'.

Suggestion
The validator should not throw in such as case when the unit is NX_ANY.
Does not cause harm for downstream processing but clutters the output unnecessarily.

[lukaspie]

We currently require a valid pint unit (with the specific restriction that we use the same unit registry as NOMAD). Once pint gets unpinned in NOMAD, percentages will be allowed. In general, I dont think it is a good idea to allow units that are not compatible with NOMAD.

[mkuehbach]

At the schema level NX_ANY states "do not be picky about the unit" irrespective which pint or RDM solution is chosen.
Constraints on the "how picky validation is config" when aiming for use without RDMs, multiple RDMs, or NOMAD also not necessarily need to be the same like it is currenty de facto assumed.
The validator warns even when using the latest pint version (0.24.4)

[lukaspie]

This is not about the version, it is about the registry we are using. NOMAD will eventually update that as well.

What I am trying to avoid on a practical level is that we have nxs files created locally (without any warnings) that then gets uploaded to NOMAD and create a bunch of warnings. That will really confuse users.